You need to set your dreamcast up with the PlanetWeb browser so that it will call your ISP - see getting online.
For some games (e.g. Quake 3 Arena) you will have to import a US version as the UK PAL versions are tied in to dreamarena. With other games (Phantasy Star Online apparently) you can use a PAL copy. The table below summarises which version of game you will need. There are notes on some of the games below the table. I take no responsibility for an inacuracies in this, so if you buy one of these and it doesn't work, don't blame me, but please let me know if I have got some of this wrong.
| Game | Versions with free access |
|---|---|
| Chu chu rocket | None (you need to connect through DreamArena) |
| Daytona 2001 | US should work. PAL version is not out yet but there are reports that it will not have online functionality. |
| NFL 2001 | US (apparently) |
| Phantasy Star Online | PAL (UK), US |
| Quake 3 Arena |
US |
| Toy racer | None (you need to connect through DreamArena) |
MrGoat has written a guide to getting online with 0800 access. It has been posted to the uk.games.video.dreamcast newsgroup.
With the US version of Quake 3 you will not be able to connect to the UK servers. Your best bet for lowest lag is probably to connect to the German servers, but even so it is not as quick as when using the UK servers. You can find the IP addresses of servers to connect to at http://www.ugvd.btinternet.co.uk under "Beginners", "UGVD servers" and are often posted to the newsgroup uk.games.video.dreamcast.