Do you mean you want the drop down list in a cell? If so, write your list in some part of the worksheet, then click on the cell you want the list to appear in.
Now click DATA>VALIDATION and you'll see a field with a dropdown called Allow:
Pick LIST from this and then click in the SOURCE field, then click onto your sheet and highlight the list you wrote. Then press Enter and OK.
Now every time you click on the cell you validated, it'll have a drop down list
Audiojoe
My gift is my song and this one's for you