I think you need your LL membership number to register, but I've never been given mine, and having looked at the forum, I've never bothered to ask for it to be honest - always found this one far more educational and lively.
You need the number that's inside the cover of your weight loss record. I joined and have spent a total of about 30 minutes getting lost and not enjoying myself and haven't been back. It wasn't very userfriendly, and believe me I know my way around a web site!
I am not a fan of the LL website, as others have said it is not user friendly. I will take a look when I can access the RTM area in the next couple of weeks.
I have been on and off there a few times, not much point whilst in abstinence as it is not half as friendly or informative as this, but the RTM stuff is really good on there, so I do use it a bit now - just not the forums.
I registered and posted a few times but hated the interface and the structure of it.
I also got ignored totally on a local thread because I hadn't posted an avatar featuring my picture and they didn't 'trust' my user name so I bowed out and stuck to this place which has been so much more useful and friendly.
I found that there wasn't really much interaction, just people posting their weight losses and no conversation or discussion. I got a bit bored to be honest.
I joined there at the start of foundation, if in fact it's the same place as I don't remember putting in my membership number. Anyway, I felt it was very quiet and as others have said there was not much interaction. I then looked about for something else and found here. I came here just about the end of foundation for me and it's been a godsend so never felt the need to go back to the other one. This place rocks....
I go on there and read the threads occasionally - but only when I'm at work and very bored - and only because it's about the only forum in the world that for some reason isn't blocked by our IT department It's still dull, still not at all user friendly, and still poorly laid out, just in case anyone was tempted!