On the OD&D Forum someone once asked, "What should be on a character sheet?" to which I replied, "Lines to write on :)"
Seriously, the only thing that has grown more in size over time than the typical RPG character sheet is the software used to create it. I used to think that extensive multi-page character sheets were the cat's pajamas, but over time they increasingly appeared as cluttered and distracting. I tried introducing a simple, relative spare D&D 3.5 character sheet to my grad school gaming group, but they preferred the "official" ones from WOTC.
When I first started role-playing, the character sheet was a 3x5 index card. The entire time I've played in Prof. Barker's Tekumel campaign all we ever used for character sheets were 3x5 cards. It's possible to scoff at them as being too small, but I think that's their secret: they keep character creation and conception relatively simple. There's only so much that can go onto a 3x5 card, and therefore only so much time to be spent on generating a character to fit on said card. From an "old school" perspective, it's definitely the way to go - and it seems like other people have figured this out already, as seen here, here (okay, it's Savage Worlds), and here (5th post down, if someone gets the link unbroken, please let me know).
I've got my own 3x5 character sheet for D&D, which can be found here; print on cardstock and then cut to size.
4 hours ago