Thanks, talk to me Will. I only want 0.51 bitcoin, how can I pay you?
unfortunately Paypal and other mechanisms like that can be reversed so you'll struggle to find anyone who is willing to accept that for bitcoins, even for such a small amount. As a result, most people will only accept bank transfer or trade with people that they already know/trust. I would highly recommend that you go to
http://britcoin.co.uk - pay the money you wish to trade (0.51 is less than 6GBP you'll have to transfer) into the account details on the site, then just buy them there and transfer them into your wallet. It's no slower than any other method, unless you can somehow persuade people that you can be trusted. Sorry but there's a lot of scams on the internet and not a lot of trust after the recent hacks.
Good luck!
Will