uzumaki,
You can look at the business end where the ports are and Cisco will have a lable telling what router it is.
ALL 26xxXM routers are Fast Ethernet, some 26xx routers are 10 (Ethernet) and some are Fast Ethernet.
And as vipergg said using the show commands!
Also 26xxXM routers tend to cost more $$$$$$ when compared to 26xx routers.
You also might want to post in the Cisco router forum and not the switch forum........
Hope this helps!
E.A. Broda
CCNA, CCDA, CCAI, Network +