Just picked up an HTC myTouch 4G Slide (AKA Doubleshot) from craigslist. Probably still one of the best Android phones with a physical keyboard you could get... which is a shame, because it's somewhat old at this point. Hopefully HTC will make a successor to this, because the physical keyboard is the one big thing they still have most of the other big Android manufacturers.
CyanogenMOD 9.1 (based on Android 4.1 ICS) just went stable a month or so ago! There are many instructions on how to get CM9.1 on your Doubleshot... this is the one I ended up using:
From there, you can pick up halfway through the CM9.1 instructions at: http://wiki.cyanogenmod.com/wiki/HTC_Doubleshot:_Full_Update_Guide