I had an idea somewhat inspired by other MMO's, and thought I'd post it here.
It would be fantastic to have an option on your character (possibly in the right-click portrait menu) where you can set your "Gaining" option from Experience to either Reputation or Gold.
Naturally, the benefits to this would be obvious at 80, as if you didn't need to get gold, you could switch to "Rep" and add a percentile of your "XP gain" to reputation instead.
But the benefits could be even greater at lower levels. Let's use a few examples.
Example 1 - Level 29 player is low on money, and can't afford the training and mount at level 30. They also really want a faction mount from another faction. They can right-click their portrait, and select "Gold" under the "Gaining" option, allowing them to lock their experience at it's current point, and instead gain gold from quest rewards, as well as an increased percentage of gold from mobs, based on how much experience that mob was worth.
Once the character had the gold required, they select "Reputation" from the "Gaining" menu, allowing an additional 5% (or whatever percentage is appropriate) of their experience gains from quests (or mobs who give rep) to count toward their reputation instead.
Example 2 - A level 80 character has recently purchased their Epic flying mount, and no longer has a burning need for the amount of gold they gain per quest. They right-click their portrait, and select "Reputation" ("Experience" is greyed out, as they can no longer gain XP). The level 80 can now enjoy increased reputation gains from quest rewards, or from killing mobs which give reputation.
Example 3 (Possibly) - A level 80 character wishes to level an alt. They create the alt, create an "Experience link" to their level 80 character, and select "Experience" in the drop-down box on their level 80 character. The level 80 now has a percentage of the experience they -would- gain from their quests filtered to their alterante, to a maximum of one level per day filtered.
As you can see, an option like this would solve many MANY issues related to reputation gains, "twinks" being leveled, and money at low levels (or for new players).
Just my $0.02
Here's the link: http://forums.worldofwarcraft.com/thread.html?topicId=16137188288&postId=161356079238&sid=1#0