Sure.
Go to
ClickBank Marketplace - ClickBank and browse the categories you are interested in. Look in the top 20 results, below that will likely not be worth the effort.
Find a site with a lousy sales letter and rewrite the letter. Get your own domain, carefully choosing a good name, and put the page up with your affiliate link, linking directly to the purchase page, not the other sales page.
One tip I got from Marc Quarles is that the lower the refd: %, the worse the sales page is. It's not a 100% sure method, but a good indicator.
If you want to learn some advanced affiliate marketing techniques, look at:
Affiliate Project X- six figure secrets exposed Day Job Killer... its about to get interesting...