Talk of a 64GB iPhone 4 is nothing new; Engadget spent some time with an apparent prototype a couple months ago, and obviously, Apple would have no trouble making a 64GB model in production quantities if it wanted to -- look no further than the iPod touch for evidence of that.

The latest tidbit comes courtesy of third-party Verizon retailer Russell Cellular, which has been circulating a memo this week referencing a 64GB capacity in the same breath as the old 32. We've now gotten the same memo (albeit in different formats) from multiple tipsters. Clearly, we wouldn't put it past the author of the memo to have simply dropped the ball, meaning to type "16 and 32gb" instead of "32 and 64gb" -- those kinds of typos happen all the time -- but the launch seems totally plausible considering that it'd take Apple very little effort to make that change on the assembly line. In other words, even though development of the next iPhone (whatever it ends up being called) is obviously well underway, there's no reason to think that Apple, Verizon, AT&T, and everyone else wouldn't mind giving the current model a summer-long shot in the arm courtesy of an easy capacity boost.

Could this be tied to the hush-hush Apple Store goings-on over the past week? Possibly -- or it could be a running change that Apple chooses to launch silently in the next few weeks. More on this as we have it.

[Thanks to everyone who sent this in]