Smalltalk is such a great invention that I believe it is essential that we make it obsolete.
I'm mostly using Squeak for some research in advanced software structuring and composition, and for Ubiquitous Computing-related research implementations. I built my first UbiComp application in four days. "Porting" it to the iPaq simply consisted of copying it over via ftp.
On the side I've done some font-related work, among other things. This began as I read about Microsoft's ClearType and got interested in the technology behind it, sub-pixel rendering. My implementation of SPR for Squeak is part of this package: High-quality font support. BitBlt is so powerful that the resulting Smalltalk code that does the SPR rendering is some 25 lines long.
A long time ago I played around with trying to make Squeak look better–make that: no longer horrible. Screenshots of SqueakNew Look