You’ve received that email, “Please print, sign, scan, and return.” Possibly it said FAX – but like me, you just can’t wrap you’re head around using a FAX in 2010. So you fire up gimp (or xsane), scan a page, crop it, save it; repeat for N pages; then spend 10 minutes reading the absurdly obfuscated ImageMagick man pages to finally stitch the images together into a PDF, and return to sender. You do this once, and the memory of it provides a very significant mental barrier to ever repeating the process.
I had to do this again today for a pair of documents. The Simple Scan tool caught my eye and I gave it a try. It’s pure genius, in an “OMFG why did it take 10 years for this to appear?” kind of way. Simple Scan handles the intermediate files behind the scenes, crops all the pages to the same size, displays a thumbnail of each page you scan, and finally saves the document as a PDF. Like, wow. Thanks Simple Scan!