Does anyone use software to track cell phones within your company? I would think it would be popular among companies that do a lot of delivery services, but we have individuals that meet with our clients and don't really have to check in often and as of lately they have had (traffic/other) issues that kept them from making a meeting and I think if we could implement this service, we could help save the company a lot of money and make sure our people are out there working.

If you have used it, what service have you used?