In one of my posts, I wrote about the UsedRange property of the Worksheet object. I use it in almost all of my spreadsheet applications. Excel keeps track of the last cell you used during your current session, and uses it to determine the used range of a sheet. The last cell is the one you get to, when you press Ctrl+End.
I always use locally named range in all my spreadsheets, in fact I wrote a post about it earlier. I extend my love for named ranges even while writing VBA code for spreadsheet applications. Using a pure Offset function based code, or a Cell Reference based code, in my opinion, is not the best way to go. Having named ranges in worksheets, and updating them to include more data before processing is the best way to go.