Early Access Release Channels
About Google Chrome Release Channels

Google Chrome release updates to different release channels. Subscribing to the Beta or Dev channel means you'll get more frequent (but less stable) updates and you'll get to try new features first. There are three release channels:
Stable channel. Everyone is on the Stable channel when they first install Google Chrome. The Stable channel is updated with features and fixes once they have been thoroughly tested in the Beta channel. If you want a rock solid browser but don't need the latest features, the Stable channel is for you.
Beta channel. People who like to use and help refine the latest features subscribe to the Beta channel. Every month or so, we promote stable and complete features from the Dev channel to the Beta channel. The Beta channel is more stable than Dev, but may lack the polish one expects from a finished product.
Developer preview channel. The Dev channel is where ideas get tested (and sometimes fail). The Dev channel can be very unstable at times, and new features usually require some manual configuration to be enabled. Still, simply using Dev channel releases is an easy (practically zero-effort) way for anyone to help improve Google Chrome.

Note: Early access releases (Dev and Beta channels) will be only partly translated into languages other than English. Text related to new features might not get translated into all languages until the feature is released in the Stable channel.
Before You Change Channels

Back up your data

Before you switch, you should make a backup of your profile (bookmarks, most visited pages, history, cookies, etc). If you ever want to switch back to a more stable channel, your updated profile data might not be compatible with the older version.

Make a copy of the User DataDefault directory (for example, copy it to 'Default Backup' in the same location). The location depends on your operating system:

Windows XP: Documents and SettingsusernameLocal SettingsApplication DataGoogleChromeUser DataDefault
Windows Vista: UsersusernameAppDataLocalGoogleChromeUser DataDefault

Note: If you're using Explorer to find the folder, you might need to set 'Show hidden files and folders' in Tools > Folder Options... > View.
Enable anonymous usage statistics

Please enable sending anonymous usage statistics in Google Chrome. The statistics we gather have no personally identifiable information. The aggregate of all the stats for all users in a release channel really help us understand how stable the release is and how people are using any new features.

Choose [Wrench menu] > Options, go to the Under the Hood tab, and check the 'Help make Google Chrome better by automatically sending usage statistics and crash reports to Google'.

Subscribing to a Channel
Download and run the Google Chrome Channel Changer (http://chromium.googlecode.com/files/chromechannel-2.0.exe).
Click the circle next to the channel you want to get updates from.
Click Update to save your choice.
Click Close.
In Google Chrome, click the wrench menu and choose About Google Chrome.
Click Update Now to install the current channel's release.
Restart Google Chrome.

http://dev.chromium.org/getting-involved/dev-channel