Up until now most of the custom ROM love has gravitated towards the flagship Xperia X10. However, there are now a number of xda-developer ninjas porting custom ROMs to both the X10 mini range and the Xperia X8.
There are a number of different custom ROM’s currently in progress so hopefully it shouldn’t be too long before we have a stable Froyo ROM for the X10 mini’s and X8. They already have most stuff working (including Wi-Fi), but the camera appears to be a sticking point. For those interested in following their progress you can click here, here and here.
Thanks t-rex and Mihkel!