Some myth-busters, based on several comments in this thread (you can call me biased because I rep part-time for Epson printers, but here it goes):
- Epson printers DO NOT use thermal technology. They use Micro Piezo technology, where high-frequency electrical impulses dispense the ink out of the cartridge and into the printhead. Thermal technology on the other hand, is employed by all other competitors, where the printer heats the ink in the cartridge to form a tiny pressurized bubble that injects into the printhead. There are pros and cons to both technologies. MP technology requires fewer nozzles because they are fired with more frequency. The heads tend to clog quickly as a result if ink isn't consistently passed through them (requiring a head cleaning) Thermal technology needs more of these nozzles because the nozzles must alternate between their firing and cooling phases (these things get WICKED hot).
- The R200 and R300 (same print engine; they just differ in features) have a 3-picoliter minimum droplet size (not 5, like previously mentioned). Unique to Epson is also their variable droplet size technology. The printer driver computes the optimal combination of droplet sizes to be dispensed out on the page, which optimizes ink consumption (the photo models work with 8 different droplet sizes). All other manufacturers use fixed droplet sizes.
- About the "ink diaper" thing: Epson and Canon both rely on this because the print head is a permanent part of the carriage. This means that dozens of cartridges will be using the same print head. Both manufacturers remedy this limitation by a small amount of reserve ink in the cartridges to clean the nozzle paths. Epson for one, has historically NOT rated its cartridge life by ink volume (in mL), but rather by estimated printed page output. Their cartridges actually contain a small amount of "reserve" ink for cleaning the cartridges on power-up that supposedly won't affect its projected page output. Of course, this fact can be debated. In contrast, HP and Lexmark both build their printheads onto the actual cartridge using a thermal mag strip. The supposed advantage of course is getting a brand new print head whenever you replace the cartridge. But this has also historically made their cartridges more expensive than Epson and Canon.
- Refilling cartridges is fine for people who print mostly documents, but it's awful for photos. There have been several independent lab tests (including one conducted by Wilhelm, a very respected source) that have proved that aftermarket inks tend to fade significantly quicker than geniune inks sold by the manufacturer. Aftermarket inks don't contain all the chemical technologies found in the geniune inks. And why would a major manufacturer freely publish this information if there's profit to be made? The printer business strives on the Gillette razor model: sell the product at below cost, but rape the customers on the consumables. And for the record, Epson cartridges with the Intelliedge chip (most models now) are nearly impossible to refill yourself. The chips on the cartridges need to be reprogrammed and you have to get the ink density JUST right or you risk spilling ink and/or damaging your printhead.
Now in regards to finding the best photo printer for your needs, I'd suggest making a subjective comparison at a store. A rep is usually present who can show you printed photo samples. In my experience of working on printer sales floors, my Epson products tend to be slower than the Canons, but have always provided unmatched photo quality. The ink costs are roughly the same when you consider cost-per page.
A frequently made comparison is between the Canon i960 and the Epson Stylus R300 (similarly priced models). Again, this is a pros and cons battle and in the end it'll be which YOU prefer. The i960 is fast and a breeze to use. The R300 has some additional features not present on the Canon, like built-in media slots and cropping. You have to pay $20 more for the i900D to get these features from Canon. Plus, the R300 has the flexibility of direct CD/DVD printing (on compatible media) and its USB direct port supports external devices like Zip and CD-RW. Not available on the i900D (its USB direct port only supports PictBridge).