How to get a cell to display the date of the first day of the month

I basically want a cell that displays the date of the first day of the month as a date cell.

So today it would be 7/1/2009

Thanks for the help

Edit:
After a search i found out this probably won't work because what I am trying to do is get the number of work days Month-to-Date. I was going to use networkdays but apparently it won't take a date field? Any help would be much appreciated