I wrote a simple Meeting Cost Clock after having a little search on google for a simple one (I actually found this one after writing mine). It's easy to use, you enter the number of participants, the average salary for those participants, then click start. It's a little rudimentary, the JavaScript is probably a little rough, but it'll serve me right.

I've styled it using iPhone universal, a CSS framework for making iPhone stylee pages, so one of my colleagues can open it up on his iPhone in our next meeting.