Three years ago I bought what was then the latest version of the VuPoint Magic Wand portable scanner. At the time it was a special on one of the home shopping channels, but you can find these scanners on sale all over.
I love it! You can do jpg, pdf, color, black and white, adjust the dpi. Upload to you computer via wifi or usb.
This scanner has given me high quality images and is really easy to use. All you do is pass it over the document you want to scan, so you can easily do business cards, receipts, brochures, photos, etc. I think the newer version has a preview screen (mine doesn't). VuPoint makes a variety of portable scanners, so if you go to their site, you'll see some scanners that require you to feed the document. The WAND doesn't, that's one reason why it's great.
The company's site is vupointsolutions.com