Hi All, i'm not sure if i'm way behind the times, but i have just bought some of these for my trip to Bali tomorrow...
http://www.packmate.co.uk/packmate_roll_bag.htm
They are special bags that you put your clothes in and then roll them up or attach a vacuum cleaner to to get all the air out.
I tried a few different brands and a different types (rolling vs. vacuum). Obviously the ones using the vaccum do a better job and keep your clothes a little neater, but the ones that you roll to expel the air are more practical for going to remote locations.
I got a dozen t-shirts down to 1 inch thick! It means for the first time ever my bag does not look full and i can actually take enough clothes so i dont stink by day 3.
I got a selection pack of 3 of these bags for £5, i reckon you'd need two sets, so for £10 your clothes are organised and easy to pack, plus when you have dive gear in your bag too its all separate and waterproofed.
I also amused myself by shrinking pillows to next to nothing in the vacuum bags.
i give them 10/10