Redesign of the Coca Cola logo for the 21st century, only if its legal to touch of course.

This is probably way too obscure but I think would be a challenging battle:
Take Georgia (or any font with an /f/ with a standard ball terminal) and redesign the top of f so that if a dotless i follows it can not be mistaken for /fi/.

I like the ligature suggestion.
Another one could be, given some definite letters, choose a well known typeface which is tied with a particular style and make them in another style.
Examples: Franklin Serif, Garamond Sans, Eurostile Slab, etc.

Another one: reinvent/improve the @'s design.
(see http://www.typophile.com/node/65886)

Or, expand the asterisk to at least five symbols.
(see http://www.typophile.com/node/65861)

I'd love to see what everyone can do with the Coca Cola logo!

In a given typeface (say, Times New Roman or Myriad), invent new forms of letters so that the letters presently more-or-less indistinguishable in upper- and lowecase (CSVXZ) have distinct case forms.
(That came from http://www.typophile.com/node/33647)

How about numerals for Barf Bold by B. “Hap” Kliban?

@eliason: your suggestions are always on the verge of typographic subtlety! :-)

Another one:
after the "album cover meme" (one of my favorites), and the "book cover meme", I think we could have the "movie poster meme"!