I came across this site the other day when I was browsing through a blog. It's actually quite interesting and could be useful if you know where to place it on your website.
Examples of uses:
1 - After each blog post. You can have a link to your tip jar after posting a highly informative post on your blog. Anyone who feels you've helped them tremendously just might be generous enough to tip you for the information!
2 - Forum signatures. If you're a very helpful forum member, you can have a link to your tip jar on your forum signature or profile. You never know, you might just come across some generous forum members.
