I've bougth a few month ago a Touchatag RFID reader, a cheap USB device. It's reported to work on Windows / MacOS but not GNU/Linux. Here's a solution to use it on Debian.

You need to install some packages :
apt-get install python-pyscard pcscd pcsc-tools python-pycryptopp python-serial python-crypto

Then download the latest release of RFIDIOT (RFID IO Tools) here and simply extract it.

Plug-in the reader and start pcsc_scan, you should see something like that :

found one
Scanning present readers
0: ACS ACR 38U-CCID 00 00 

The "0:" is the reader id, so ctrl+c out of pcsc_scan, edit RFIDIOtconfig.py, jump down to the readernum= directive, and change that to the correct id given by pcsc_scan.

You should now be able to test your reader using one of the contributed script such as multiselect.py.