How do you rank on google image pages? also, i have seen plenty of sites with just pictures with adsense, wouldn't that be againt TOS
I always put alt attribute to all images within my site. Actually I get lots of traffic from Google images.
Use the Alt attribute for images however they are not intended for keywords! So don't abuse them. Make a short, brief description on your image that would best fit the image. You can also watch this video from Matt Cutts as he discusses the importance of alt attributes to images. Hope that proves useful enough. - Gr
Trying to use words like "funny" purposely to try and get common users that type those words looking for images isn't going to help much. Slightly more specific phrases and words will narrow the results and allow your website and image to e closer to the first page.
agree with hersheys yes this is the the way to point search engine crawlers towards your image and additionally try to keep your image name as your keyword(s). Thanks