A jailbroken app called ‘iUsers’enables the iPad to behave a little more like your Mac by supporting multiple user profiles.
The tweak puts a user profile button on the iPad’s homepage, where users can be switched fairly simply. For now only apps, music, and other content are shared between users, but the data inside the apps (game hi-scores, etc.) are user specific. iUsers’ developer is currently working on implementing more granular user data. The tweak is making its way to the Cydia marketplace, but if you’re eager you can find the instructions to installing iUsers over at BlogdoiPhone.
Hopefully we’ll see this natively in the iPad soon, and maybe Apple will decide to Sherlock it at some point in the future.