I use RTM for personal, work, class assignment, you name it. I typically keep them separate, but I've found that when I'm out and about, I can accomplish stuff for any one of those things. For example, picking up something I forgot grocery shopping, or returning someone's call.

So I created an "On the Go" smart list with criteria: {name:call OR name:brainstorm OR tag:buy OR tag:return OR name:buy OR name:return OR tag:fu} ['fu' is my shorthand tag for "follow up"].

When I get in the car (before driving), I bring up the On The Go list and see if there's someone I need to call, something to buy or return, someone I need to follow up with or just something I need to brainstorm about.

It's especially great for tasks like "Call Mom" that don't have to have due dates but still show up "On the Go".