Apple should offer some sort of reward to those who convince others to "switch." In the past two weeks alone, four people with whom I have a close relationship have either purchased a Mac or made it known that they plan to in the very near future. I propose that Apple give the referrer, or persuader as it were, some sort of monetary kickback, even if it can only be used toward Apple products. After all, they offer a referral program for .Mac, so why not extend that to notebooks and desktops as well?
Of course, even if this idea never comes to fruition (which it won't), I will continue to laud Mac OS X (I can't help but to talk about it; I think my friends buy Apples just to shut me up :P), but it would be nice to get something in return. All it would take is a simple question to be answered when one registers their product: "Did any particular person influence your decision to purchase this product?"
Granted, there is no real incentive for Apple to offer this sort of program because those who do 'advertise' their products aren't going to stop simply because they aren't rewarded. But then again, people certainly would push Apple's products a bit harder if they got something above and beyond the "I told you so" line in return, which, quite frankly, usually is enough for me. :P
Hell, this idea should be extended across all product lines (mobile phone carriers/manufacturers, PDAs, headphones, music, etc.) — I'd be fucking rich.