Keeping personal expenses in check when on business travel

I have a funny life. At home I'm dirt poor, never go out to eat, or to the movies or to much of anything that isn't related to a kid's performance.

But I travel frequently for business. I stay in nice hotels, eat at fancy restaurants, and have this second life of luxury. On my company's dime. I don't abuse my expense account. I'm honest about what I spend, and I'm not extravagent compared to my colleagues.

But the "extras" in a business traveller's hotels really add up. Like $4 for a bottle of water in the room. $15 for a movie. And don't even get me started on the minibar.

So I bring my cheap ways with me. If I have time, I stop by my public library before  my trip to get a DVD to watch on those late evenings after a business dinner when I'm too wired to sleep. Or, if I don't have time, I grab a favorite DVD from our collection (from the the time before we stopped spending money on such things). Or, failing that, I may even buy one from iTunes or rent from Amazon. Still much cheaper than hotel pay per view.

I buy a bottle of water and a snack, if I need one, at a local drug store.

I use my corporate credit card for as many expenses as I can so that I don't have to wait to file my expense reports to get reimbursed. I forgo the rewards I might earn if I put them on a personal card. But since my personal cards have balances (I know, I know) I also forgo the interest that the issuers would charge me.

I even save money for my employer. Instead of paying $15 a day for internet access in the room, I bought a Wireless USB dongle from Virgin Mobile, which usually ends up being much cheaper, and more flexible. (Typically, the hotels I stay in have free wireless in the lobby, but not in the meeting rooms or guest rooms.)

If the cost is the same, I use my frequent flyer airline and my rewards point hotel. The rewards are slow to come, but may help me bring one of my kids, or even Mr. Poorhouse, on an exotic trip some day. 

The one thing that is tricky is bringing gifts to kids of friends who live in my destination city or bringing souvenirs home to my own kids. I probably spend too much on this kind of thing. Any of you have ideas for keeping the cost of guilt presents down?