Recently I wrote about using OS X "Image Capture" for photo Scanning. I've gotten some praise for the results, so I figured I'd detail my current scanning workflow.
My goal is fairly quick image acquisition of about 3,000 low quality 3x5 and 4x6 prints. Speed is more important than quality. The very best images, probably less than fifty, will be rescanned using a high quality Nikon Film scanner. After scanning is completed the prints will be discarded but I will keep the negatives in a single large binder.
Scan output is, for now, manged in iPhoto. If Aperture ever allowed us to edit date metadata I'd use Aperture. [foul language censored]
I thought I'd be doing this using a sheet feeder, dropping the prints in and returning hours later. I can't find a decent one for working with prints; the only one I can find is the SnapScan and they've historically not imaged prints. I'm using an old Epson 1660 Photo scanner, but if my secret weapon continues working I'll invest in the Epson V700 -- if I do that I might try bulk film scanning instead.
My secret weapon is the combination of an 8 yo with a Lego habit, OS X "Image Capture", and Aperture post-processing. Ben is willing to work for low wages  and Image Capture is simple enough he can go through 20-40 scans while I work on an adjacent machine.
He scans at 400 dpi with no adjustment and the images are output as TIFF. The results at this point are mediocre.
When Ben is done I drop the TIFFs into Aperture and optimize one image: auto-level, sharpening, noise reduction and contrast enhancement with some mild color saturation adjustment. I then apply the set to all images. (I think I can save it as a standard setting but I haven't done that yet. iPhoto 8 can also be used in a similar way, but iPhoto 7 would be very inefficient.)
A few minutes later Aperture is finished. I quickly review the results but usually I'm done with the initial work. I then crop the images fairly extensively. Lastly I export as 98% JPEG and I delete the TIFFs.
The JPEGs are renamed using 'A Better Finder Rename', since Image Capture adds a counter to the string "Scan" I rename "Scan " to YYMMDD_RollNumber_# where # is the counter produced by Image Capture. YYMMDD is based on the date of the roll, and Roll_Number comes from the prints. The roll number binds the roll of JPEGs with the set of prints with the set of negatives. I don' t capture the actual print or negative number, the roll ID is good enough for my purposes.
I then drop the JPEGs into iPhoto and add ratings, date estimates, and comments. I choose one date for a range of prints and add it with a 1 minute separation using iPhoto's batch update. The iPhoto roll information includes the YYMMDD_RollNumber identifier. The five star prints will later be replaced by VueScan negative scans from a Nikon CoolScan V.
The resulting images are impressively better looking, on screen, than the original prints.
 Amazingly this is legal for one's own child. I should mention that once he can do this without my help his wages will rise to whatever he can get from the neighbors for their scans. Of course I could start charging him for the scanner...
Update: This article on scanning with Aperture is pretty good. Note that Aperture has a big date problem. You can't revise the acquisition date. True, you can set a date in the IPTC extended image creation date field, but Aperture mostly ignores that field value. I use Aperture for editing, but iPhoto for archiving.