Those are the two trades:
Jun 22, 2011, 22:14:01 5000.00000 0.00
Jun 22, 2011, 22:13:02 500.00000 0.01
Probably someone spending a fiver to test the trade-matching algorithm posted here:
http://forum.bitcoin.org/index.php?topic=4984.msg260989#msg260989(I'm guessing the first trade was for 0.001 BTC, or Britcoin lets you buy 0 bitcoins?)
I've always assumed I'm posting an offer I'd like to deal at, rather than some kind of minimum/maximum level. Seems fairly straightforwards IMHO.