While Floodgap is temporarily down, I've been keeping track of TenFourFox's development via Cameron Kaiser's blog and saw he's released the first beta for TenFourFox 7, about the equivalent of Firefox 7 beta 4. I've been using it about a day and as always am really happy with it.
Visually it's almost the same, except they've now removed the http:// from the urls. So Mozilla's address bar team continues to fix problems that didn't exist. I haven't noticed any remarkable speed improvements on my ridiculously low-end system. Twitter definitely seems faster, other sites I couldn't tell. The best news is that RAM usage is a bit lower. It's been between 150 and 200 MB for me, though it's only been a day. I'm sure tomorrow it'll shoot up to 450.
So give it a download. You may have to upgrade your add-ons. I had to install a new Flashblock, which thankfully had been updated to be compatible. And stay safe out there. It's a jungle of SSL certificates.