Once you scan your document or receipt, it appears as a PDF file in the application. You then rename the file and decide whether to put it in a folder with other documents or receipts. We can't say the software's superslick, but it is easy to use, and it's easy to drag and drop PDF files wherever you want them to go.
The Windows version of the ScanSnap manager comes with some extras, the most important of which is optical character recognition software that lets you turn scanned PDF documents into Word or Excel files. For example, we took an old manuscript that we didn't have stored on disc, digitized it into a PDF, then fed that PDF into the included ABBYY OCR program (it's not the latest 10.0 version of ABBYY's FineReader, but it is version 9.0). Windows users also get business-card reader software that lets you feed business cards into the scanner and turn them into digital contacts (it works well except when a card has odd lettering or characters on it).
Overall, we were pretty pleased with the results of the ABBYY software, though we did encounter one glitch where it turned all "I"s into "1"s. You can do a find and replace if the software makes any errors like his, but things get a little tricky when you're faced with a situation where you have both "I"s and "1"s throughout a document.
While we found the S1500 a pleasure to use and easy to store (the paper trays fold inward into the unit to conserve space when not in use), we should point out that it does have some limitations. For starters, it can't accept oversized documents aside from longer legal-size pages. Since the scanner is designed for 8.5x11 inch paper (as well as the aforementioned legal-size paper), anything wider than 8.5 inches isn't scannable. Also, while it can scan photos, it doesn't scan them as well as a true photo scanner (we ended up with some visible scan lines with an 8x10 photo we scanned in) and it turns them into PDFs not JPEG images. On the other hand, we were impressed how most everything else looked, including receipts that were reproduced in vivid detail.
Also, as noted, Mac users don't get the important OCR extras; the scanner simply turns documents into PDF files and the desktop software helps you organize those files. (Initially, the S1500 was not compatible with Snow Leopard version of Mac OS X, but Fujitsu has recently provided new drivers.)
For those looking for something even smaller and more portable, Fujitsu also makes the S300M, which costs about $250. However, the S300M is geared toward receipts and short documents.
For about $400 online, the S1500 isn't cheap, but it's reasonably priced for what it does and how well it performs. The fact is, if you're looking to get out from under all the paper that's overwhelming you--or just taking up space--the Fujitsu S1500 is a small but powerful organizational weapon that you'll soon find indispensable.