When Sudoku puzzles first appeared in our newspaper, I wondered whether solving them was simply following a standard algorithm, or whether there was a 'puzzle' to it. So I made a spreadsheet that automated the 'obvious' steps of clearing overlaps and picking out singletons. What happened is that the puzzles are rapidly consolidated to the tricky parts. (Easy ones can usually be solved with these two steps.)
The spreadsheet uses macros in Excel, which are very powerful (and also a serious security concern). If you would like to know more and how to view these so that you are convinced that this isn't a virus, check out my Macros in Excel page (this page was written for some statistical spreadsheets that I shared out, but the information is the same. The back link won't take you back here though - use your browser's back button).
The actual Sudoku spreadsheet