I recently got one of these because of my work with Uni Threads but you can use it for pretty much anything. Basically it's a way to accept credit cards from anyone through your phone and it deposits it directly into your bank account. It takes 2.75% so if your selling anything under $100 is pretty legit. It works on Iphones, ipads, itouches, all androids and the sickest thing is that they send you the device for free if you sign up. Even if you don't have one of those phones or whatever you can still make an account, get one sent to you and if you need to accept a payment borrow a friends phone or whatever.
Check it, http://www.squareup.com/c/rosie