Chip Pearson posted some macro code that would do it:

http://groups.google.co.uk/group/mic...3070ba01635091

or
http://tinyurl.com/b9orl

He has two posts in that thread. One post is the code that does the work. The
second post includes code to add it to the rightclick menu.

If you're new to macros, you may want to read David McRitchie's intro at:
http://www.mvps.org/dmcritchie/excel/getstarted.htm

Sloth wrote:

I discovered you can use the ctrl key to select non-adjacent cells. Is there
a way to deselect certain cells? Sometimes if I am selecting many cells I
might select an extra row on accident. In which case I need to start over
selecting the cells. Also if I select a range of cells (for instance, A1:G9)
can I deselect certain cells? For instance A1:G9 except A3,B7, and F9. I
know this seems like a silly question, but I would just like to know if there
is an answer to this.

--

Dave Peterson