I need to create a formula that will automatically calculate the number of
tickets sold per month that takes into account the current date. The
number
of tickets sold since July 1, 2007 is in a cell which is continuoslu
updated.
As of today, October 9th, we have sold 5251 tickets which will result in
around 1595 tickets per month. But this sure has me stumped, any ideas?

Here is another possibility... it calculates the actually number of months
passed prior to the current month and adds to that the fraction of the
current month that has passed to date (day of month divided by total days in
month) and divides that into A3 (where I am assuming your total number of
tickets sold is kept).

=A3/(DATEDIF(DATE(2007,7,1),TODAY(),"m")+DAY(TODAY())/DAY(DATE(YEAR(TODAY()),MONTH(TODAY())+1,0)))

Rick