Google Webapp now support multiple accounts. A step closer to mobile nirvana if you ask me.
I have four different Google accounts. A personal one, a work one, another one for work, and a public one which gets bombarded with spam. And from time to time, I have to access them and I hate having to sign out of one account, sign into another, and then, if needed, sign out again so I can sign back into another.
I just tried it but it has not shown up on my browser yet. Well, I did some checking. You'll have to go to settings and enable multiple accounts use. After that, it should be just fine.
The account that you sign in first will be your default account. So, your Google+ or Reader will be directed to your default account.
Also, you can set up a separate URL for each account for easy access.
Source: TUAW, Google.