I was like you. Then i bought a flash and damn did it make a difference. I just got the jessops 360 for £79 from (you guessed it) Jessops.
Works a treat.
Just debating this myself. Don't shoot much indoors, but Xmas is looming and a lot of family that I'd like to get shots of ..get a fast lens, or a cheap flash??
yeah i'm probably going to do both, i found a 420ex on craigs*st awhile back for 80 bucks i should have snagged it.