Hi Kea,
Sorry, didn't see your question about the Gilis below - hope you are still around to read this. I don't know if you saw my JBR on Gili Trawangan (in September archive of forum).
From what I saw, 90% of the places in the Gilis are cheap to stay at (30000 - 60000 rupiah a night for fan and cold water, 100,000 upwards for air con, depends on the season), so really it depends what you like. We stayed for one night at the Pondonk Lita in Gili Trawangan. I would definitely recommend this place as one of the cheaper of the cheap options - it is clean, and you get a nice breakfast included. No working shower or hot water, and just a very loud large fan. It is set a bit back from the main strip on Gili Trawangan, and costs about 40,000 a night usually I think (they charged us 60,000 as it was the last room that night in August).
If you want something slightly better, I would recommend the Tir Na Nog (right on the main strip by the beach). We stayed here for the last four nights of our trip. Friendly staff, clean rooms, sheets, towels, warm water, and air con. Still cheap. Nice bar, reasonably lively, good food (not indonesian, but they do good pancakes for breakfast, included). We paid 250,000 a night, but I'm sure you would get it cheaper if a) it wasn't the last room available, and b) it wasn't high season. It wasn't that expensive anyway.
For most of the cheap accommodation over there, you kinda just have to turn up and see what is available that day. You could try to book some places (maybe some of the dive resort bungalows, like Blue Marlin or Dream Divers etc) but for most, you just turn up.
If you want anymore info on the Gilis (accommodation, how to get there, what there is to do, whatever), just email me at cammy1982@hotmail.com. I would definitely recommend making the trip over there, it was one of the nest parts of our last holiday.
Camille x