Valve are after some playtesters to help them out a bit, specifically with testing prototype hardware and both "released and unreleased" versions of their games.

Adding to the other frequent rumours of hardware development at Valve, the fact that they are recruiting community playtesters (in the US at least) on mass, should tell you something about what they are up to. Burton Johnsey of Valve posted on their forums to give everyone the news:

"We're looking for folks to come to Valve and playtest both released and unreleased versions of our games as well as play around with some of our hardware prototypes. If you have interest in stopping by (most sessions last around an hour), please fill out the survey below. We're looking for people local to the Seattle/Bellevue area, but you're welcome to fill out the survey no matter where you live as we may have plans for remote playtests in the future.

Thanks for your interest in helping us make better products!"

He also added that they are looking to expand and add international playtesting in the future. For now, if you are in the US or just interested in what the survey is like, you can go here to apply.