Bitstream is working on a mobile browser called Bolt, based on WebKit and compatible with pretty much any J2ME-compatible handset (read: almost everything). CrackBerry ran it through its paces, and it looks promising.
The version you see above is for BlackBerry, though functionality should be almost identical between platforms. Like Skyfire of Opera Mini, Bolt performs a good deal of page optimisation server-side, meaning that it's fast. In fact, compared to the Bold's stock browser, it's really fast. Rendering accuracy looks about as good as any other WebKit-based mobile browser (Safari, Chrome, S60 default browser) but appears significantly snappier than its competition.
Bolt is in a private beta for now, but you can request an invite here.
J2ME is nearly ubiquitous, barring the obvious iPhone/G1 exceptions. That means Bolt will run fine on your BlackBerry, S60 and Windows Mobile phones, among many others. [CrackBerry]