The N900 supports

Optimized for WCDMA 900/1700/2100
Quad-band EGSM 850/900/1800/1900

# GPRS class A, multislot class 32, maximum speed up to 107/64.2 kbps (DL/UL)
# EDGE class A, multislot class 32, maximum speed up to 296/177.6 kbps (DL/UL)
# WCDMA 900/1700/2100. Maximum speed PS up to 384/384 kbps (DL/UL)
# HSPA, maximum speed up to 10 Mbps (DL), 2 Mbps (UL)

As long as your provider is operating a GSM service on 850, 900, 1800 or 1900 mhz frequencies you should be able to use the N900 with EDGE and GPRS.

Anyone using the N900 with AT&T and many T-Mobile subscribers (myself included) will be using EDGE. Personally I want more speed but I will take what I can get. For faster downloads you can use WiFi hot spots that may be available.