A couple weeks back we launched Multiple Inboxes, an experimental feature in Gmail Labs that you can use to customize the different "inboxes" you see in one view when you log into Gmail.

If you forward all your work or school email to Gmail, you can use Multiple Inboxes to see your two accounts separately within the same browser window. Here's how:

1. Turn on Multiple Inboxes from the Labs tab under Settings.
2. Set up a filter to auto-archive all mail sent to your work or school address.
3. Customize one of your multiple inboxes to show mail sent to your other address. To do this, go to the Multiple Inboxes tab under Settings and set up one of the panes to search for mail sent to your other address.

4. (Optional) Use a "custom from" address so that replies will be sent from Gmail but as if they're from your other account. This way, your coworkers or classmates won't know the difference.

I use Multiple Inboxes to keep track of email sent to my college alumni address which I forward to Gmail. I used to filter, label, and auto-archive all these messages (my alumni frisbee team listserve gets tons of mail), but found that I rarely looked at the relevant labels. Now with a separate "inbox" I can see them easily without cluttering my primary inbox.