Yeah, just visited the BT site. Monthly charge is indeed £29.99 (but you can also factor in that this includes the ISP charge, so for me it's effectively £23.99 extra). The installation is via the DIY route, and you will be charged £85 for the USB DSL modem, two DSL filters and all the relevant bits of wire. Also worth noting is that this frees up your line for voice calls as they use a different end of the spectrum.
If you apply before May 31st you get the £65 "activation" charge waived, but they're not taking orders until next Tuesday (March 5th).
I think I shall be taking the plunge this time round. Getting sick to death of dialup!