I have a habit of keeping receipts of every sales transaction I make. This is good for taxes, returns, rebates, billing, resale, and just trivia. After a decade or so it really piles up.
Several years ago I built my first PC, a Pentium 133MHz system with a Micronics M54Hi motherboard and a screaming Quantum Fireball 7200RPM 4GB SCSI drive (which later failed so I guess the screaming was a bad thing). This was one awesome Doom playing system. The advantage of SCSI over IDE was the number of devices a port could support (7 instead of 2), speed, and the ability to brag that your system cost 10x what everyone else bought. Of course a 50 pound, 30in high tower case with 3x the space needed was essential.
I also bought a HP ScanJet 3C (C2520A) 600dpi 8.5x14in SCSI scanner. This alone was about $900. While the scanner did get some use it mostly just sat on the shelf collecting dust and depreciating. It was rather large and I didn't have enough space on my desk to keep it handy. Several PCs later I bought a Visioneer OneTouch 8100 USB scanner for $50 - which was a waste of money as Staples had it on sale a month later for $25. This worked well and was much smaller but I still didn't get around to catching up with the paperwork. A unique feature of the 8100 was that it's power jack matched the plug on my Toshiba laptop power supply. However the power supply output was not compatible and after getting the plugs mixed up one day I had to buy another scanner. This time I got an Agfa SnapScan 1212U which has worked rather well.
Last week, while tripping over another box of paperwork I decided to finally start scanning things in. I'm using Xsane on Ubuntu 8.04 (Hardy Heron) and it's working rather well. I fit as many receipts as I can on the glass then preview them, draw a selection box around each in the Preview window, then hit the Scan button. Some of the receipts are too long for the Agfa so I installed an Adaptec SCSI card and hooked up the ScanJet. Xsane (0.995) doesn't let you switch between two scanners except at startup but you can run two instances of it simultaneously. It keeps track of preferences for each scanner separately too. Some of the documents I'm scanning have several numbered pages and Xsane has a numeric filename auto-increment function. It's not very flexible but it does the job. My only complaint is that some hotkeys, like Ctrl-V, are used for changing settings instead of the default copy/paste functions that most apps use so I have to use alternates like Shift-Insert. This makes copying and pasting filenames into the save dialog boxes annoying.
I find that scanning most things in at 300dpi grayscale and saving them as JPEGs works best. For items where color is important I use 600dpi. The ScanJet has one design flaw in that it's pad is white while the SnapScan's is black. The white pad causes printing on the back side of receipts to show up when scanning the front so it takes some fiddling around with the contrast and brightness settings to suppress it.
I'm not just scanning in receipts either. I'm also scanning contracts, notepads, holiday greeting cards, photographs, and user manuals I can't get PDFs for. It takes a long time but DVDs take up a lot less space than file cabinets.