simple, download file manager app like "ASTRO" from Market

then, get your .apk files from various sources, place it anywhere in your SD card, then launch ASTRO, point to the location inside your SD which have the .apk, launch and install..

u buy a smartphone but u dun have data plan?!
dat is not veli smart of u isnt it?

like buying sport car but let ur grandma use..

u can use public wifi oso bah...

I know what U feel 
You can go to .
Settings -> Wireless & Networks -> Mobile Networks

Tick use 2g -> Go to Access Point Names

Change APNs
Eg.

Digi
you turn it into Digit(anything else) for the APN.(Remember to save)

By now you should saw the data up down logo disappear.
Cahnge back APN to use back data.. Some people recommend apps to do that but I found it always fail to work for me and slow .. Maybe is me only >.<

try looking for vignette, you can get the free version from google, i use it as replacement for CM6 camera, superb, and many things to play, you can even capture full 5mp resolution pic, touch focus etc...