I am looking for a digital camera that i can take with me when i scuba
dive. I am not looking for a pro camera but something that a normal
person (me) can use. I would be printing the pictuers to a 4 x 6
prints and would be sending them by email, so something like 2.5 MP -
4 MP would be enough.

I would be taking it to a depth of 40-90 feet but i would like it to
have a little extra depth just in case. This would be my 2nd camera
since i would be using my canon S500 for land pictuers.

Hello Sulafa

Thank-you for your question.  This was a question I recently had to
answer for my own use as I wanted to try underwater photography.  With
the specifications you mentioned there are unfortunately very few
solutions I could recommend but the ones I did find are mentioned
below.

From my research it appears that the major camera manufacturers
generally prefer the housing option where you place your normal "land"
digital camera in a specially designed waterproof box.  Have you
considered this option?  The DigiDeep.com site below has the best
guide to these housings.

When one of the major manufacturers does produce a "waterproof" camera
it is usually what I would call "splashproof", they either can only go
to depths up to 5 feet or cannot actually be operated under any water.
 This is definitely something to be aware of when purchasing your
camera.

Additionally, there are a couple of excellent forum postings here for
people wishing to get started in underwater photography (from these
you will notice that most people use these housings):
http://wetpixel.com/PNphpBB2-viewtopic-t-5762.phtml
http://wetpixel.com/PNphpBB2-viewtopic-t-1659.phtml

Of the dedicated cameras that are available these are generally
regarded as the best:

1) Sealife DC310 3.3MP Underwater Digital Camera
· Land Mode, Sea Mode and External Flash Mode
· Instant delete option after each picture in both Sea and External Flash Modes
· One-button operation
· Expandable with all ReefMaster lenses, flashes and accessories
· Depth tested to 200 ft / 60 m 
http://www.amazon.com/exec/obidos/tg/detail/-/B000098XGP/wwwpalitoycom

2) Spypen atol
"Make outdoor adventures unforgettable with Spypen atol 2.1. The
accredited case doesn?t just protect the digicam from water, sand and
dirt. You can even take it for a dive to a depth of 30 meters (or 3
atmospheres). Just open the viewfinder and focus ? simple. And you can
call up all the features using the metal controls. Back on dry land,
the submergible device turns into a modern, multifunction digicam in
just a few steps."
http://www.spypen.com/index.phtml?artikel=0061&tg=3&skriptname=artikelinfo

If you have any further questions on this subject please ask for
clarification and I will do my best to help.

Other useful links:
http://www.seapix.com/digital1.htm
http://www.backscatter.com/hostedstore/static/html/backscatter/articles/articles_home.html
http://www.livingroom.org.au/photolog/tips/underwater_digital_photography_tips.php
http://www.marscuba.com/uwdigital.html
http://www.digideep.com
How to get started -
http://www.wetpixel.com/module-pagesetter-viewpub-tid-1-pid-23.phtml

You should also look in to a company called Scuba Sonics.  The make
underwater notification devices that are useful to get the attention
of others when you find an interesting subject to photograph and want
to share.  Check them out at www.scubasonics.com