You've answered the first question, your megapixel requirement.
Other questions to answer, this will narrow things down for you:
1. What's your budget? With these cameras there is no bargain, you get what you pay for. All megapixels are not created equal, manufacturer reputation, lens quality, ease of use and camera features are important.
2. How much zoom do you want? How much wide angle do you want?
3. How small do you want the camera to be? Small is good for a climber but there is a point of diminishing returns in features and image quality.
4. Do you want to have manual exposure controls available? Or is automatic only ok?
5. Do you want a weather proof or water resistant camera?
Once you've thought about the questions go to
http://www.dpreview.com/
and scan through the camera models and specs to find the cameras that meet your criteria. Feel free to contact me directly if you have questions.
-moss