What is the proper phrasing on an invitation to request money in lieu of gifts?

I am not a Google Answers researcher.

From various "Manners" and "Etiquette" sites, one theme rings loud and
clear: soliciting money from guests is bad. To hear those who know
tell it, it is the worst thing to do as the people you are inviting
are guests (not customers).

According to this article,
http://www.utahbrideguide.com/planning/articles/no_nos.asp, for
instance, the best thing to say is, "No gifts please."

I fear this isn't what you want to hear, and I don't blame you, but
society and etiquette don't always see eye to eye.

Of course, proper phrasing is in the eye of the invitation holder.

How would you like to be invited to come as a guest to a function and
be told "No gifts, please, but money is fine."? Phrase it the way it
would sound the best to you if someone sent you the invite.
(Otherwise, smile and accept what they gave you of their own
unsolicited good-will and quietly return the gifts for credit
somewhere.)

What would you think about, "In lieu of gifts a love offering ba$ket
will be available for cards."?

I think most people would agree that throwing a party for yourself and
asking for money is tacky and bad form.  Anything that conveys this
message would be improper etiquette.

I agree with Crythias.

Soliciting money from guests cannot be done in a tasteful fashion.
Calling the solicitation a "love offering basket" does not, in my
view, make things any better.

What about at a birthday party for an Eighty year old woman who needs
nothing as far as gifts would go and would have a difficult time
returning them or exchanging them? still no?

Some wedding invitations put the word "Presentation" on them. This
typically means that they are expecting money as a gift.  You will
still get the diehards who will not give money and will give you a
gift instead.

Don't know if this applies in your situation. You didn't mention if it
was a wedding or not.

First, congratulations on the 80th Birthday. Kudos and more years to come.

Respectfully, the people whom you might invite may ask what they might
bring. To be ultra polite, "Nothing but a smile."
"No, really, can I bring a gift? What could she use?"
"She is rather happy with the amount of items she has."

The people who truly know the guest of honor best should already know
what she needs as a matter of course. Otherwise why invite strangers
to her party and suggest money to attend?

Also, if such a ba$ket exists, kindly not make it a center of
attention to add a feeling of insecurity or obligation to your guests
who may not have participated in the "hint".

No, I'm not a manners expert. I'm not even close. Guests are guests
and customers are customers and donors are donors. Each knows whom
they are and expect to be treated accordingly.

As well, those who care enough to invite people to this gathering
should care enough to assist with the disposition of any heart-felt
gifts. Of course, that's just an opinion from a commenter.

I just have to throw in my two cents worth. At 80, who gives a dang
about etiquette? I just attended an 80th birthday party a few months
ago. The invitation said "no gifts, please". Had it said something
like you have already suggested (offering basket), I would certainly
have taken some cash, figured the person could use it, and been glad
they had the smarts to say so, rather than allow me to take none, or
to take some gift they couldn't use. But then, I'm more the practical
type. I just don't feel that, in this day and age, people ought to be
offended by something like that. If they are, then I wouldn't want
them at my party anyway.

The old-fashioned etiquette in this matter makes sense to me.

Mentioning money in an invitation sends a subtle suggestion that
guests are not welcome unless they come bearing cash. That might not
be the actual meaning intended by the sender, but the recipient is
likely to take it that way.

If the person being honored is, as mentioned, eighty years of age, it
is entirely likely that she has friends who are not in the best of
financial circumstances. Such friends may feel very uncomfortable in
attending the party unless they can scrape up some funds.

I once received a wedding invitation that included the exhortation
"Bring your love offering to show that you care!"

I did care. Quite a bit. But, at that time in my life, I was in dire
economic straits because of severe health problems. Rather than risk
offending the bride and groom by showing up without the desired
contribution, I fibbed and said that I wouldn't be able to attend the
wedding because of illness.

In similar situations with my own grandfather we've decorated a large
box and suggested that everyone bring stratch tickets to deposit in
the box instead of a gift.  He LOVED it!  Who wouldn't?  Some people
brought $5 some brought $100, it didn't matter in the end because they
all went into the same exciting box!

This discussion is just what I need. I am planning 80th birthday party
for my mother-in-law and I attached a leaf shaped post a note to the
inside of the invitation that says " For your convience a money tree
will be available"
I felt that the "for your convience" gave enough leeway  for folks not
to feel pressure. But honestly, she really would get a lot of fun at
having some money to spend for whatever she desires. A person on
social security just doesn't get much chance to spend guilt free. I
believe I will take the chance of being tacky - for her.

I had the same problem myself and followed the advice I found below. 
Worked a treat in the end.  Anyone who asked (which was just about
everyone) was directed to the list

Cut and pasted from: http://www.bespokecards.net/

Should I mention a gift list in the invitation?
Wedding etiquette decrees that you should not do this because gifts,
whether wedding or otherwise, should be received as a ?pleasant
surprise?.  Mentioning lists or gift registry details in the wedding
invitation violates this notion and often leads to offence being
taken.  The accepted practice is to inform parents and close friends
of the gift list details.  Most guests will by default contact them
for details and you will still end up receiving what you wished for.

Should I include the gift registry detail card?
Again it violates the notion that a gift should be a pleasant
surprise.  Also, gift registry cards are little more than commercial
advertising for your gift list provider.  Your wedding invitation
should be setting the tone and expectations for your wedding day.  Do
you really want these cards detracting from this?