AmeliaG,
what you need is one of the Casio EXILIM line cameras! the best camera around for snapshots - go for S3 or Z4 models.
3.2 - 4M resolution
really, really lightweight - S3 is just 70g
good on lowlight too
Z4 has pretty nice zoom feature as well...
check'em out here:
http://www.exilim.com
hope this helps
thank you
Avion