I just got back the 20"x30" print of the panorama I shot at the top of Diamondhead (a series of photos stitched together automagically with Autostitch).
It looks absofriggin' AWESOME. I mean, wow. Completely blown away at the quality of the print. Looks like a professional poster.
I goofed when I sent the image for printing through iPhoto, though - I forgot to manually crop or pad the image, so they just cropped it to fit the aspect ratio of the print, chopping off the mansions at the foot of Diamondhead, and the hotels at Waikiki. Next time, I'll send a 4x6 aspect image, likely with white blocks at the top and bottom to pad the image so the full pano fits onto the 20"x30" print.
Ofoto obviously noticed the croppage, as they slipped in an informative document into the package, explaining about cropping and the various aspect ratios. They also mention an option called "Zoom & Trim" which can be set to "off" to turn off autocropping. That option apparently isn't exposed by the iPhoto "order prints" interface...
It cost about $30CDN (delivered), and took about 2 weeks to get to me. I might also shop around for places that can do the print locally for instant gratification.
Update: Duh. Next time I order a print, I'll just stack 2 or three panos to approximate the 4x6 aspect ratio, and pad the little bit extra as needed. No reason to throw away half of the print! :-)