I've used Google docs for live drafts and they've worked great. This is the first year Yahoo has the features we need to run our draft (i.e., keeper and traded picks), but Google docs worked nicely for us up until this year.
Simply create a spreadsheet, enter keeper info and traded picks, share the doc with your league and you are good to go. I always like to color code each team so it's easy to see traded picks.
You can see our final results from last year
here. We even had two supplemental picks after the 10th and 15th round that we award for second half prizes. With all the colors it's almost a work of art. Um, a fantasy baseball work of art, anyways.
"The game has a cleanness. If you do a good job, the numbers say so. You don't have to ask anyone or play politics. You don't have to wait for the reviews." - Sandy Koufax