On Day 5 of my 365 Days, I was talking about portable scanners. A great addition to bring along is a portable printer. For desktops, there are many All-in-one Printer, scanner, fax from a variety of companies, yet for the portable printers, there are really two major players around, HP and Canon. The Canon portable printer does have a scanner module that you could switch with the ink, but the scanning takes longer and not as good of a quality as a dedicated portable scanner.
Each of their devices have an advantage/disadvantage over each other. The HP portable printers are usually more heavier at about 9lbs and bigger compare to the lighter 4.4lb Canon printers. The HP printers have a few more features like Bluetooth and is about $100 more expensive. The latest Canon printer is the Pixma IP100 and sells for about $200 while the HP printer is the Officejet H470 with a few versions that offer wireless or bluetooth for about $300.
I have a Canon IP90, which is one model older then the latest for about 5 years and am pretty happy with it and don't think would upgrade anytime soon. It is pretty light and the black cartridge can print about 500 pages before needing to get replace and the color print out are pretty good. I saw a lot of money by refilling the ink cartridges myself taking only about 2 minutes for black or color and cost about 25 cents in ink compare to paying $12 for each cartridge. Also have a portable battery that last for about 200 prints.
If you need to print often on the go, getting a portable printer would be a great investment. I would recommend paying an extra $100 for the battery pack and bring an extra set of ink just in case of emergencies.