This is for United States Laws.  If I wanted to use the picture of a
celebrity and put it on a tshirt to sell for commercial purposes, is
that okay?  If I did not take the picture, what makes the picture
available to the public domain?

Cafepress.com seems to not want celebrities pictures but doesnt seem
to mind politicians.  I wonder if this is just so they are safe.

Spreadshirt.com would be the service I am leaning towards using.

I think its okay to use politicians images without their consent and I
think it would be okay with a celebrity (say for example Jennifer
Aniston).  What if the picture was a drawing that I made?  Is it okay
if it reference is made with the celebrities name?
I think this seems to be a gray area.  What is the boundaries of this
gray area.  Lets assume that the tshirts do very well and attract
attention and consternation of the celebrity.  How should I go about
this to stay on the right side of the law and out of trouble?

What about using the images of characters from a tshirt...what about
mentioning their stage name or should I just leaving that out?

Thanks

A researcher will give you full details.  I am just a Joe Schmo commenter.

It is not illegal in that you would not face criminal charges. 
However, you can be subject to civil litigation.

When the Princess Diana Trust tried to sue Franklin Mint for producing
those ghastly 'Diana dolls' - they lost the case resoundingly, and got
stuck with costs.

Of course Diana was dead - which might have had a bearing on things.

Honestly, this seems to be one of the more contentious legal issues
(at least in entertainment/freedom-of-expression law) around today.
Since so much is happening--and so much on a case by case
basis--you're probably not going to find a cut-and-dried Yes-or-No
answer, and you really, really ought consult a legal professional
rather than rely on any advice you get from the internet.

Private individuals (like celebrities) certainly have the right to
some measure of control over their own images (the right of
publicity), especially in commercial uses.  But free speech/free
expression rights certainly apply, and should allow reasonable usages
of others' likenesses for certain uses--parody, satire, reportage,
etc.

Public officials (like politicians) are generally held to have a
greater responsibility toward the public than private figures, and
therefore courts may be more inclined to deem permissible a usage of a
public figure's image than a private figure's. This may explain the
different kind of treatment of politicians vs. other celebrities
you're seeing in the world.

(But this has become an issue that's come up with folks like Jesse
Ventura and Arnold Schwarzenegger--people who were private citizens
who had rightfully been used to controlling their image but who later
became public figures subject to perhaps different standards.)

Anyway, the answer is (as it often is in legal issues) "It depends."
But in this particular case, since you're dealing with issues actively
being discussed and debated in the courts, I think the answer is "Man,
it *really* depends, and you're better off consulting a real
expert..."

The media can use images of celebrities because it is news  - in most cases.
You want to use them to make money, which is different.  Maybe some of
them will be pleased, but maybe not.  Their faces are their property. 
You need their permission.

Of course, nothing posted here is legal or professional advice, as you
can read in the disclaimer below.

Some of the information in this answer to a similar question may be of
interest to you:

http://www.answers.google.com/answers/threadview?id=457264

If you are using a photograph (or a drawing by someone else) without
permission, you risk violating copyright law.  (A work is in the
public domain if it was first PUBLISHED before 1923, or if it was
first PUBLISHED between 1923 and 1964 and the copyright was not
renewed, unless the rights holder was not from the U.S.)  In other
words, unless the person who created the image has given permission
(perhaps by making a voluntary announcement that the work was being
dedicated to the public domain--and this is VERY rare), the image is
protected by copyright.  If your infringing activities generate income
over a certain level for a certain period of time (e.g., $1,000 in six
months--unless the numbers have changed), criminal penalties can
apply.

The relevant area of law is called "rights of publicity."  This is
governed by state law.  Most states have some degree of protection of
an individual's rights of publicity.  The longest term of protection
seems to be 100 years from the time of the person's death.  You need
to think not only about the law in your state but the law in any state
where you are sending shirts, advertising shirts, etc.

In short, I would be very, very careful--and I would consult an
attorney who understands "rights of publicity" law.

You can generally find public domain photos of politicians easily
because photos on government websites are public domain unless it's
stated otherwise.  To get photos of celebs you pretty much have to
take your own, purchase the rights to use somebody else's copyrighted
photos or find someone who is willing to give you permission to use
theirs for free.