Why a beer? Well it seems to me that if you were here (or I was there), and you liked the program, and we met in a pub, you would probably buy me a beer. So why not "paypal" me the price of a beer, and I'll do the buying.
How much is a beer? You tell me. I rekon beer is a pretty universal currency, so the answer is whatever it costs you, there at home. Whatever you like really. The Paypal link below will let you enter any amount you like.