Vimeo has been a popular high-quality alternative to YouTube, particularly with content publishers and bloggers. Unfortunately, uploading videos to Vimeo has left one particular (and rather large) group of potential viewers in the dark: iPhones.

Like many video upload sites, Vimeo relies on Adobe Flash for its content delivery. YouTube got around this limitation by also offering iPhone-friendly H.264 versions of its content in addition to Flash. Not wanting to leave out a large swath of users, Vimeo has begun to make the same transition, much to the jubilant cries of bloggers everywhere.

“We’ve been working on it for the last few weeks,” the company proclaimed today. “This is sort of the prelude of offering Plus members iPhone support; and in the future, an app.” For now, Vimeo is focusing strictly on making its Staff Picks and HD video showcases iPhone-friendly, but that situation will change soon enough: “In the future, like the next several weeks — maybe longer, we’ll be offering Plus users the option to transcode their videos to an iPhone version too.”

Of course, the Vimeo love-fest isn’t exclusive to the iPhone — Android users can also get in on the fun. But as Danny Allen at Gizmodo points out, that may not be a big issue with Flash 10.1 on the way — although the verdict is still out on whether iPhone users will have something else to rejoice about when that time comes.