Smalltalk YX is known to work on many platforms at this time. However, lately i've been working to port it on PocketPC with a small graphical workspace.
It took me about 3 days of work but now it works very well. Cross compilation has been easily done using CeGCC on Windows with just some changes in the VM.
The only problem is that Syx needs to be installed into the root device to work, it's not working in other directories, but i think this is the last problem to care about.
A plugin has been added, called WinWorkspace, which is a native Windows GUI containing a text box for both the input and the Transcript, and a DoIt button to evaluate the code. This plugin also works on Win32.
I think Syx can be easily ported to Smartphone as well without many changes.
Here you can find some screenshots: http://code.google.com/p/syx/wiki/ScreenShots
Stay tuned with the next 0.1.3 release, bye.