Help: allow a blank as an option in a drop down list

I'm trying to create a drop down list with different priorities for clients to choose from (high, medium, low) but I would also like to have a blank as an option. How can I do this?
I am using 2007 if that matters at all.

What I've tried:
Making a list on a seperate sheet and including a blank cell while defining the name of the list. Whenever I set up the data validation after this it deletes the blank cell and only allows the options high, medium, low.

Any help would be appreciated!
Thanks,
Laura

try putting blank at top of list rather than end
e.g.
'blank'
low
medium
high

tried it. no luck.

In you "named range" list of possible choises, be sure to include a "blank" cell

I've tried that too. I've tried putting the blank in every possible spot and it always gets deleted by Excel. Is there something that I can type in the cell that Excel will format as a blank?

I actually tried the space thing too.
But I just figured it out. I'm not sure how it managed to work, when I tried all the logical solutions and none of those work.
I put a character in the extra cell I wanted blank and then defined the name and did the data validation, after that I just deleted the character and magically it stayed as a blank!
Who would've known?!

Thanks for everyones help!