Membership

www.castingnow.co.uk/

Lets you join for free, but it DOES NOT let you apply for any jobs or even view full job details.
What you can do for free is create a profile with one picture (which you cannot delete unless you upgrade!) and be accessible to casting directors.
If you are hoping to get a job through casting now you have no choice but to upgrade

Membership prices:

£3.99 per month if you pay for 2 years in advance (£95.76)
£4.99 per month if you pay for 1 year in advance (£59.88)
£6.99 per month if you pay quarterly (£20.97)
£15.99 per month if you pay monthly

I have my profile on their website (since October 2011) but so far had no jobs whatsoever.
I know that sometimes it takes time, but the truth is, I didn't find interesting stuff on their website to apply for.
My guess is that no one monitors this website and you get an awful lot of listings for magazine stories, tv quizzes and other crap like that.
It's everywhere you look. If you click Acting Auditions or Extras Work you shouldn't see listings for SO MANY unrelated "jobs".
I find it very annoying and unprofessional. There should be a separate category for that kind of shit
I cancelled my membership (it remains active until my subscription runs out). I have better things to do than scroll through all that and hope to find something interesting.
Saying that, I'm sure loads of people found work through them. I personally DON'T RECOMMEND IT, there are other sites that let you apply for jobs for free and have more relevant stuff on their websites.