The Wheel of Time, Omega World and Farscape XP systems are variations of the 1st ed. d20 Star Wars system. If you add or subtract percentages to the suggested amounts, you can tweak it to taste, though some players I have still possess a fetish for getting "credit" for every combat they win.
AEG's Spycraft system also had a decent chart for Ad Hoc rewards that focuses on "XX" x character level for accomplishing objectives. Spycraft also has a great system called "Backgrounds" where a player can trade off skill points for a subplot. When the subplot comes into play, the PC gets XP. If the GM ignores the subplot for 3 sessions, the PC cashes out with a XP bonus.
nopantsyet said:
Boy was I wrong! I guess it's just one of those sacred cows that's hard to make sacred burgers from. One of my players response was, "Well, it just sounds lazy to me." And I said, "Well, yeah." As if DMs don't have enough to do without having to calculate XP all the time.
Funny how those who don't have to do the work like to judge how easy it must be.

I told a fellow who said the same thing "And when are you going to start running a game?" His answer was "Oh, I don't run games."
That comment almost ranked up there with the best one I heard yet.
"Well, that can't be right. My old GM never used such a rule."
"It's right there in the book."
"It can't be right, 'he' never used that rule."
"Your GM made up a house rule, look it up and you will see it."
"Oh, I never read the rulebooks, that's for the DM to do."
It turns out the player never /bought/ a rulebook either.