You first might determine how many you need and see if you can get a company vendor to give you a special rate.

If the photos are to be the whole front cover, that is more problematic. If they are for insets and punch shots most 3+ Mp P/S will cover the rez range.

Colour, if your're Design/Graphics Dept has set up for your (or others) Canon systems, consistent color might be easier to acheive with Canon with DiGiC processors.

Durable can mean different things to different people. If this means droppable, waterproof, can be left in the car for days, bounced around in a brief case (can you tell I've done Tech Consulting) then the price range better be in the diposable or wear item category.

Olympus makes some nice waterproof tough cameras, but the color is, well, not always correct.
They have a new Stylus coming out after the first of the year in a 5+Mp size that could be promising.
Some of Olympus non-stylus cameras are very highly usuable, and produce fine pics.

Now salesmen like something special. A lot of the Sony and Pentax cameras are pretty foolproof, and many can be called sleek.

Vivitar, yes Vivitar, markets some inexpensive large Mp Cameras that take fine photos,

All the point and shoots have a limitation that you should consider. They need Light. The flashes are generally pretty woeful except for fill and if the don't let you pick the ISO (Many don't) they may jump to 400 (or one set went to 320?) and then another problem or fifty arises.

This past summer/fall I saw a lot of photos that came from the newer Sony cameras (I'll get model no. if you need them) that were taken under dreadful light of people at weddings and reunions that were very usable.

I've use a Canon S50 for a small pocket camera (though its not real small actually) and had great success with it and its larger brother the G5 when I didn't want to haul the dSLR and cases. The G5/G6 also use the same Speedlites as the Canon dSLRs. Real Handy, but not exactly simple cameras.

The Canon A series (75-95) work quite well from my limited time with a couple.

Hope this gives you something of a start. - C