Austria

Default data rate
Unknown, but per MB; I burned through 10 euros in 3 days. You can get data turned off on their side if your phone doesn't have an option for it; it was successful for my G1 but according to them it doesn't always work. Text messages are .20 euros to send, free to receive. Calls are .09 euros/minute to call, free to answer. There's a minimum of a 10 euro deposit on the sim card per transaction.

Availability
T-Mobile SIMs can be purchased in their own shops.

SIM sizes
Unknown.

Tethering
Unknown.