I am travelling to London for only 10 days for business. How can I make phone calls? Should I rent a mobile?

I was planning on buying a phone card and making calls to home/work in the US from the room or any phone. However, when I want to call or text my business colleagues I was thinking I could rent a cell phone. How and where do you do this? Does it makes sense for a short trip? How much does it cost?

You could do that. But there is a cheaper way. When I was in the UK a few months ago I managed to get a cell phone on a pay-as-you go plan for a very cheap price, cheaper than renting a phone. In fact, when I researched renting a cell phone the cost they charged for the calls was astronomical. Another option is to upgrade the cell phone you use here to be a tri or quad band phone - then you will be able to use it in the UK (as well as many other international destinations).

Phone cards are a pain. They are expensive and they run out quickly, and there's never a place handy to buy a replacement when you need it.

The last time I went to Europe, I just had Cingular activate the international service on my existing GSM phone. It has to be an "all band" GSM phone. It costs about five dollars to activate and I don't recall what the per minute charges were, but it didn't run my bill up, extravagantly, and the convenience was excellent. I was even able to use it for Internet access on my PDA as, at a minimum, GPRS is available most places in Europe, and certainly in GB.

We called the US several times, and made frequent calls, locally for reservations and travel information. I even had a couple of cases where we didn't have a place to stay, and I made reservations for hostels with my PDA while we were on the train, on the way.

renting a phone is a drag, buy a pay as you go cheap phone it will last the trip and be reliable.