I have a piece of paper that had a note written on it in pen, and the
writing has been bleached out by the sun, but the indentation is still
there. How can I make the writing visible again, in the most
aesthetically pleasing way? (This is a note from a celebrity to a
friend of mine & I'd like to frame it as a gift.) Thanks.

Someone with sufficient skill with PhotoShop could do it.  My son is a
PhotoShop adept, and he's been doing volunteer work restoring family
photos salvaged by victims of Katrina.  He took on several photos in
the category of worst damaged.  Some of them were just unintelligible
blurs, but he managed to bring nearly complete images out of them
through many hours of painstaking labor.  The results were truly
astonishing.

A similar process could restore your friend's message.  But it would
be a copy, not the original.

It's a paradox that notes written in pencil, though erasable, are more
lasting than those in supposedly permanent ink.

Archae0pteryx

Ultra-violet light might enhance the image of the ink (not the actual
document).  If so, perhaps allowing the sheet to be photographed. 
Again, just a copy, but maybe it could be framed with the original.

Ha, someone agrees with me:
http://www.plowden-smith.co.uk/adviceline/messages/471.html

Hi psychresearcher-ga,

If it were my photograph, I would finely grate some strongly-coloured
candle wax over the area. I would then blow the wax-dust gently so
that it lodged in the indentations. Then, I would very gently warm the
photograph until the wax melted in place. I would try this on several
unimportant photos first.

If it were someone else's valuable photograph, I wouldn't dream of
trying anything like this (which I why I have not posted this as an
answer).

Regards,
eiffel-ga

Here is a site with suggestions:
http://www.hrc.utexas.edu/about/conservation/resources/faq/#inks

If the whole text is indented (unlikely), clever use of side lighting
could make ite legible and allow a photograph.