Here's some starter suggestions:
1. Browse the real-estate windows....its a great way to built up market intelligence for your next property investment.
2. Pace up and down the street, but in line of sight from the wait site....just in case she comes out and can't find you.
3. Find a nice quiet seat, again in line of sight, and get the newspaper out that you brought along, just in case.
4. When traveling this is a great oppotunity to read the travel guide literature you picked up so you can quickly suggest where to go next once she emerges.
5. For the experienced...agree on a time to meet and then head off to the pub or coffee shop for a drink.
6. This also could be a good time to check the oil and water in the car or clean up those loose branches in the driveway.
7. Book shops are great. Again if you can find one in line of sight you can always while away hours if necessary...though for extended times be prepared to buy something, otherwise they may think you are just casing the joint.
8. Like bookshops, hardware stores can be equally attractive, though in my experience they are rarely located near female shops of interest.
9. In a new country just watching the world go by can be interesting. Take note of the speed with which the locals walk, are there more bikes than at home, do they walk their dogs, what sort of dogs, how are they dressed (people, not dogs), what sorts of cars do they drive, do they chat to each other......
So I need help..., so just post your best ideas and I'll add them to my wiki