An exquisitely timed iPhone leak

And sure enough, on the eve of the annual Mobile World Congress, which opened Monday in Barcelona, a story appeared on the
Journal
‘s website that took the wind out of sails of the companies that (unlike Apple) actually bother to attend.

Even the strategic alliance of Microsoft (MSFT) and Nokia (NOK), announced on Friday, was overshadowed by the news that Steve Jobs had another iPhone up his sleeve.

The Journal‘s story, co-authored by Yukari Iwatani Kane — Apple’s current favorite conduit for such things — had several moving parts and was updated with juicy new details as the day progressed. Here are the newsy bits, as the Kane and Ethan Smith reported them:

• A smaller, cheaper iPhone: Code named N97 and due for release this summer, it’s supposed to be half the size and half the cost of the current iPhone. Kane and Smith quote an unnamed source who saw a prototype as saying it was significantly lighter with an edge-to-edge screen (i.e. no button) and could be controlled by both voice and touch.
• A major revamp of MobileMe: It might be free (instead of $99 a year), could serve as a “locker” for large media files (music, video, photos) and would give iPhone and iPad owners access to their iTunes library without having to plug into their computers.

Left unsaid in the Journal piece is that
Bloomberg Businessweek
‘s Peter Burrows and Gregory Bensinger had a version of the smaller, button-less iPhone story last week. Their device was only 1/3 smaller than the current iPhone, which is a little easier to imagine using.

Also on Fortune.com:

• Why a tiny iPhone could be a big deal
• Microsoft’s 8 previous mobile partners
• Rumor mill: iPad 2, iPad 2.5, iPad 3

[Follow Philip Elmer-DeWitt on Twitter @philiped]