Just read about this on the Electronics Bus blog,
It's a new PIC microchip with an integrated radio transmitter intended for keyfobs and the like. There are 8 preset channels covering a couple of bands: 418-443.92 and 864-869.85mhz per the datasheet (Page 361). There's an application note as well. It supports FSK and OOK. FSK mode can run up to 100kbps(!) at a power output of up to +10dBm. (About 10mw if the online conversion tool I used is right).
Can you receive FSK with AFSK demodulation? This chip would be interesting paired with code and a cheap GPS chip to make a small, low-power, cheap APRS beacon. Add a homebrew power amp for the 430 or 440mhz band and you could have a platform for a remote APRS sensor or sensor network. Although, since it's just the transmitter, I'm guessing you'd have to be careful of collisions.