I recall, on a different matter some time ago, VueScan was also a recommendation from joemike. I've downloaded a trial copy and have been goofing with it a bit. I did a scan of a full page B/W invoice at 200 dpi resolution and the result is quite good....and only 81KB. I have two scanning requirements:
1. Scanning colour and B&W documents into PDFs for use as email attachments
2. Transferring colour and B&W prints into digital for archiving family photos
The second is, of course, more critical so it'll be interesting to see some of those results.