I've updated the Excel Spreadsheet I use to keep track of my NaNoWriMo novel. It's a cosmetic update which works in exactly the same way as the tool did previously. Basically, it just looks more cool. Enter your current word count into the second column from the left (it's labelled 'Word count') and the spreadsheet will work out how far ahead or behind you are, and even plot your progress on a pretty graph. Tip: stay above the red line.
You can download this tool for free by clicking here. You'll need, of course, a copy of Excel. It might work in Open Office, but no guarantees.
And, in case you have any difficulty running it, the old version of the spreadsheet is available here.