ACM is now the proud owner of a 125kHz RFID Reader! The NAU Cards transmit on 125kHz using FSK Modulation (excellent forum post here).

Features (from the site):

• Fully-integrated, low-cost method of reading passive RFID transponder tags
• 2400 baud TTL serial interface (output only) to PC, BASIC Stamp module and other processors
• Requires single +5VDC supply
• Bi-color LED for visual indication of activity
• 0.100. pin spacing for easy prototyping and integration

I'll be posting some more information as I tinker around with it and specifically tailor it for the MSP430.