Well I was building a website for my friend's business and he asked about taking credit card payments. Long story short, we talked about using Paypal as a processor and I promised to check out the options.
While doing this I found out that you do not want to use the Donate button they have. Paypal apparently feels that only charities that are raising money for a "legitimate cause" should be able to take donations.

So I had to make my own button because "buy now" doesn't make sense and I doubt anyone would want to keep sending in payments like a subscription button does.
I made a button that says "Support Free RPGs", so far so good.
The problem is that they want you to define a set value for the donation, *ahem* I mean purchase. There was one way around this that I decided on. You can create a drop down menu that has different monetary amounts and descriptions. I decided to go with.
Buy me a coffee $1
Buy me lunch $5
Buy me a pizza $10
Buy me a T-Shirt $20
Send my wife on a date $50
I figure people might take pity on my wife. No one would hand me $50.
It's reasonably easy to set up through Paypal. I have no idea how to handle sales tax. That may never become an issue but it would be nice if I had to figure it out.
What do you think? Would you do something similar?