One of the cool surprises we get is when someone just releases a LWUIT application out of the blue. A couple of such applications came out recently that seem very cool and attractive, first is Pader Sync File Manager which has been around for quite some time. They decided to overhaul their UI using LWUIT and are prompting this as one of the main features of their new release.
It seems like a cool and useful application but I had trouble with it under Symbian where you can't really control permissions properly (manufacturer/operator restrictions are really limiting here).
The other application is MyWidz it offers a widget based experience for installing widgets on the cell phone, seems somewhat similar to the Hydrazine project from Sun.