I'm currently comparing Polaroid CZA10011 PoGo Instant Mobile Printer and Canon SELPHY CP800 Black Compact Photo Printer (4350B001). I was wondering whether there's a photo printer out there that is as portable as the PoGo Mobile printer that has the quality of Selphy.
The question you need to ask yourself is whether you'll be satisfied with 2" by 3" prints made on dye-incorporating paper (the ZINK technology) or whether you want larger (4" by 6") prints made with dye-sublimation technology. If you want dye sub results, the printer needs to be bigger for any given picture size, and if you want 4x6, the printer will need to be twice as big (at least in two of its dimensions) regardless of the technology.
Both Canon and Sony offer very compact 4x6 dye sub printers. The Sony is not as tall as the flat Canon, but it is a little wider (and more expensive), but neither can come anywhere near the Polaroid/ZINK printer in terms of size. But then, they're meant for printing photographs, not stickers (which is one of the primary features of the ZINK paper).
You might take a look at Zink printers. http://www.zink.com/buy-ZINK . They don't use standard paper, but it is a very good printer, and is ultra mobile.