I've seen it mostly in advertisements or shop signs:
Kountry Krafts
L@@K
It's Nu 2 U Resale
or in song titles:
"Thank U"
"U Got the Look"
Is there a specific term for this, besides "Annoying"? Thanks!
On the theory that someone else is bound to come along and answer your actual question, it dovetails with one I once asked on alt.music.lyrics: what's the earliest hit song title with a deliberate misspelling?
The Artist Formerly Known As "The Artist Formerly Known As Prince", Known As Prince, is notorious for the kind of titles you mention where "U" stands for "you" and "2" for "Too". But long before him, Sly and the Family Stone had a number-one single called "Thank You (Falettinme Be Mice Elf Agin)", and even that was preceded by the Guess Who's "Undun". I couldn't find any earlier examples in the broadest interpretation of rock and roll.
Leaving aside cases of "-in'" for "-ing", the earliest I've found is "Mam'selle" (recorded by various artists in 1947, the earliest and most successful of which was Art Lund), more or less simultaneous with Red Ingle's "Tim-Tay-Shun" and "Cigareets, Whuskey, and Wild, Wild Women".
Wiki calls it "sensational spelling" without really explaining why, but it sounds like it has something to do with "trademarks" and simply drawing attention to a brand name. The term probably has its roots in marketing.
See: http://en.wikipedia.org/wiki/Sensational_spelling
By the way, Ron, been wondering what that is you're holding in your avatar. I'm guessing it's either the neck of a guitar or a slide rule. But since geeks rarely wear shades, it's probably the former, huh?
It's a guitar, but at the time it was taken I owned more slide rules than I did guitars.
Fancy that ... a musician and a geek. I kinda had a hunch about the guitar, given your many comments about music in this forum. I too have a guitar (Tunes electric bass) and still have 2 slide rules, but they've been gathering dust for many years. The slide rules, not the guitar.