Range Booster

I just moved into my new apartment which offers free wireless internet. however where i live (back of the complex) the signal is weak, or sometimes not there...i got the run around at the local frys when looking for a range booster/antanae etc (something i can hook up to my macbook pro). does anybody know of anything i can use to boost the signal strenght (recieving end, usb probably)?
thanks

The only thing you could do is get a USB or ExpressCard slot wifi adaptor with higher sensitivity and the ability to add a external antenna.

The other option is get higher DB antennas or a directional antenna on the WAP (wireless access point) but since this isn't your WAP its unlikely you will be able to do this.