4 major service provider in Malaysia..
DiGi
MaXiS
CeLCoM
U MoBiLe
but i think DiGi has the best prepaid plan for not-so frequent users like me.
as cheap as RM1 per day. you can buy their broadband internet prepaid pack (if no microsim version available can always ask the provider to cut the normal size to microsim with minor fees, i did tat and no problem so far)
it goes like this..
if you top up RM10, you can use it continuosly for 2 days (RM5 per day) unlimited usage
RM30 - 10 days
RM50 - 25 days
RM100 - 100 days
so for the ease i just top up RM100 for only RM1 per day.