Originally Posted by DontUnderstandMyIpad

You could always create two seperate folders labelled 'X' & 'Y' and than place your apps in the corresponding folder. There are various apps for Twitter, facebook, browser, etc.. While this would not hinder the other person from accessing one's own content, it does give the option of having things, such as facebook seperate.

But this is of course only a crude work-around.

Or, just use the browser and log out.

If sharing email is the only concern, and you use typical webmail accounts like Google, AOL, or Yahoo, then the Better Webmail app will let you secure each account with a PIN. The reviews are good, but I haven't tried the app myself. No reason, I'm the one person one device guy Apple was targeting.