Are you just boiling water or doing actual cooking?

If you're doing actual cooking, aluminum spreads the heat far more evenly. You can cook in titanium but it will take a lot more stirring, fussing, adjusting of heat, changing pan's position on the burner to avoid burning the food in spots while leaving raw spots elsewhere. The Al pot or frying pan is well worth the small extra weight if you're cooking, especially fussy stuff like pancakes or for items like stews that you plan to simmer for a more lengthy period. Not only will the food be better, but washing the pot will be easier.

For just boiling water, Ti works fine. It has its advantage for this task in that as soon as you turn off the stove, you can grab the portion of the pot above the hot water with bare hands without burning. This feature, of course, explains the problem of using Ti for cooking. I have not found any difference in boil times between using Ti and aluminum, assuming the same stove, the same size pot and the same water temp to start. Bobito, that's not the first piece of misinformation I've heard from REI employees. EDIT, LATER: Do note that this is anecdotal information; if anyone with identical Al and Ti pots and a good thermometer wants to test this out, we'd love to hear the results!

Of course if you're using thin Al, like the KMart grease pot (beloved of budget backpackers), both the weight difference and the difference in conductability are very small. The grease pot will last only a couple of years until it's too dented, but you can buy a lot of grease pots before reaching the cost of a Ti pot.

Anodized aluminum is considered the best for real cooking.

I just boil water to rehydrate dehydrated food, so I use a Ti pot. If I'm going to be fishing, I take an aluminum fry pan, leaving the Ti pot lid at home.