Today I accidentally stumbled about Arora, another simple webkit based browser. And I'm very pleased. It's quite fast, renders webpages without errors, is google-mail, etc. compatible, and has a basic interface that's very similar to Firefox(tm).
But I think it's lean, but a true alternative and I'm writing this blog post in it - without any issues. I've tested version 0.4 in Ubuntu 8.10.