For a 4x6 print 2MP=300ppi This is about the best you will get from a printer so 3/4MP is actually a little overkill.
You can print very good 8x10 prints with 4MP (I do it a lot). With 4x6 prints it will allow you a lot of crop space (area around the edge to throw out).
In many ways for your requirements 3MP is better than a 5+MP.
1- Lower memory card cost (smaller card holds a lot of pictures)
2- Lower Noise... In general a smaller Number of megapixels
makes a cleaner picture.
If you want to go to poster size (10x14 or larger) then 5MP might be a good thing otherwise it's not worth it.
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If 3x zoom is enough then here are a few more cameras to look at:
1- Canon A75 about 1/2 the size of a CD
2- Minolta DiMAGE Xg really small but still has an optical zoom
3- Nikon coolpix 3100
4- Pentax Optio 33L (The swivel display can be really handy for
looking over crowds)
5- Kodak 6330 (The 7xxx and 6xxx Kodaks are good the others are
not as good).
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Remember pictures are not taken by cameras they are taken by photographers.
Whatever camera you get note down what things you wish were better as you use it. Don't jump into the DSLR wagon unless you really have a need for it's features and it matches up with your needs. It's no good to spend $2000 on a camera and have it sit on a shelf.
The better the camera the more you will have to do (sounds backwards doesn't it). You will need to pick the speed or aperature, you will need to decide if a flash is needed, you will have to bring the pictures into a photoediting program EVERYTIME. It's this power that puts you in creative control of the process and allows you to exceed the built in profiles of the camera. And that is why I love it.