Inexpensive/easy PTO tracking software?

I need to track PTO/vacation time, but don’t need any of the other fancy stuff that most time tracking/time sheet systems offer. Any suggestions for things to look at that are Web based?

In what kind of context? Is there some kind of bizarre accrual system? Why not just use a spreadsheet in Google Docs?

A spreadsheet is what I use now, but I want an actual system that can give me easy to use reports like “These are the people that will be absent this week” in a nice calendar format I can post on a door, etc. Something where people can go to a Web form and submit PTO requests, check to see how much is left, etc.