A few of the UK chicks are watching it on realitytvfan.org which tends to upload using zshare or megavideo. The megavideo time limit is annoying so I often watch the zshare version in spite of the worse picture quality.
Unfortunately they often have the vids removed and if that happens they don't put them up again, so past series are not generally available on there, though it's fine for watching the current one.
Some of the sites around seem dodgy. I was watching an episode on Youtube and as they did not show the whole site, clicked on the link supplied. The website was flagged red by my firewall and I couldn't close the page or firefox down without using Task Manager, so I won't be trying that one again - watchbiggestloser.com is the site to avoid.