Fiona, I use a Nathan bottle holder, that goes round my waist like a bum-bag! The people at my local running shop recommended it (maybe they just see me as an easy target as I believe anything they say!) for my longer runs....when I do them, as I always seem to need to drink loads, even on a short run. As I have'nt done any really long runs yet I can't comment on how comfy it is after a longer time, but it seems really comfy now, and the bottle is quite big. Mine just has one bottle, but there were ones that held more.