I have created a tool that accepts bitcoins on a specific address and just sends them back to you!
Not very useful looking I know but great for testing client connectivity and other things. There is a version running on testNet too.
Details are at:http://bitbounce.s3-website-us-east-1.amazonaws.com/
Address to send to is: 1MXKMMdufMYXmnrVgHCcgpqjZY8itE39HL if you want your money back instantly (i.e. zero confirms). Good to see speed of p2p network (about 30 secs each way but varies a lot).
Address to send to is: 1BEgL3j6YSzxajeyp6A5AUaqcYbN5xZRaU if you want to wait for 1 confirm - here we wait till we see your payment in a block before sending payment back.
Hope you find it useful.
(Note: it does not send all the money back it subtracts 0.001BTC to cover the transaction cost and hosting it - details on site).