Progress on the Travelling Yuppie Problem?

With the ubiquity of infinitely growing TODO lists among busy professionals, we might be able to borrow from the field of action-planning to opportunistically allow people to be more efficient.

For example, if a person had the following items on their TODO list:
1) Return curtains to Home Depot
2) Drop off Jill and Bobby's wedding photos
3) Stop by Maz Auto to figure out why my windshield squeaks
4) Return Visual Thinking to Green Library by 3/1/2006
5) Check out the Wangechi Mutu exhibit at SFMOMA b/w 12/16/2005 and 4/2/2006

Then, the following sorts of queries could be run ->
1) I'll be free in San Francisco from 3 - 5pm today -- is there anything you (TODO) suggest?
A:
i) The SFMoma is open and you wanted to see the Wangechi Mutu exhibit
ii) Bobby and Jill live in SF and you need to drop off their wedding photos.
iii) There is a Maz auto at 3rd and Townsend, you wanted to get your windshield checked out.

2) I'm driving from San Jose to Stanford today, is there anything I should remember?
i) You need to return Visual Thinking to Green Library before 3/1/2006
ii) There is a Home Depot right off the 101, if you want to return your curtains

There are a lot of other kinds of queries that could be executed with similar knowledge (so-and-so is going on vacation, is there anything I need to accomplish with them? i need to do the following N things, what is the fastest way to accomplish them?)

But, minimally, as proposed, the system would require knowledge about:
1) time
2) space
3) people
4) commercial entities (store chains, etc)