After 2.5 hours of downloading, installing, configuring and building i created my first gmapsupp.img file. :-) I used the Great Britain osm download and the cycle map rule set which i tweeked a little to include the round Berkshire cycle route. The BCR seems to have a missing tag (lcn=*) which meant that it was not high lighted. I'm very impressed with the splitter and mkgmap which run very quickly given the whole Great Britain OSM file is 2.5GB. It took about 20-25 minutes to build on a core 2 duo 1.8GHz with 2GB ram.

I've also noticed that someone has been busy mapping in Swinley Forest (South of Bracknell, GB) As this is where i MTB the effort that has gone into the single track routes is very appreciated.

I'm currenly looking for somewhere i can host the resultant .img so others can make use of it. I've noticed on the Garmin Download page that the GB cycle map hasn't been rebuilt for a while.