[smeagoly1]

From one who has used their moving home service, it is worth giving VM a call. If you get the right person, and given enough detail about your new local, they should offer you or give you enough information to swap over quite easily. I was online within 3 days after a complete move. Mind you this was from cable onto their ADSL package. It did save me a few hundred squid, as i had already just signed a new cable agreement before i had to move.
Check on VM's website your post code, to see if cable is in the area, if so it should be a breeze and just wait for the engineer date to be set.
If not, it's a time to wait for BT to install a new line, if that is the case, the ISP market is your oyster. Quite a few doing good deals out there.
I'm not one thesedays for long term commitment, as deals for older members are virtually nill, compaired to new customers on other ISPs