Selenium seems to be the mainstream tool for browser side testing and it isn't that horrible. But are there any alternatives hiding out there, even in beta phase?
Canoo Webtest is an option, although it has a steep learning curve. There's a lot more coding and a lot less clicking to generate tests than there is with Selenium.
Watir is cool, it feels like a DSL, and you write the test cases in ruby.
Here's a Google Search example to see how it looks like
Have you looked at WebDriver in Google code. It is probably the fastest alternative, beyond Selenium and Watin / Watir as it drives the browser directly in memory without the need to launch it.
You might want to look at Windmill, which is very cross browser capable. We have also used FIT and FITnesse is also quite extensively used
Sahi (http://sahi.co.in/) should be a good alternative too. It can run using javascript and java drivers. You could look at a demo video here: http://blog.sahi.co.in/
Sahi is a GREAT Selenium alternative. It works as a proxy to an existing browser and it injects JavaScript on top of your rendered page to capture events and verify presentation.
It uses JavaScript Rhino engine features of Java 5 and can be used in data driven test scenarios; supports auditing, test suites, ANT integration and does not require recorder plugin, as it works with your existing browser.