Expand.
I know, it's pretty elementary, but expanding is the top way to get a tech boost. The more tiles you have to work, the better. The higher your pop, the better...the citizens can work more tiles. And build roads -everywhere-! They provide commerce...later, more commerce with railroads. This commerce fuels scientific gain, so you can easily see how this could help your cause.
Second, I like to build every science imp in nearly every city. Sure, it might cause you to take a hit in your military growth, but it's worth it.
The tech-whore strategy is viable, but only to a point. The idea behind it is that you sell techs to other civs, thus allowing you to accumulate their wealth and dump your funds into science, all the while depriving them of scientific growth because you have their money. I've used it a couple of times, and you can get an astronomical gold advantage (which does kick ass when rush-building in democracy), but it's often more frustrating than it's worth. With the patch, the AI trades with itself in the middle of your turn, thus dulling the tech-whore dominance. Also, I've made very lucrative deals, where the AI civ gives me 150+ gold/turn for a tech, then declares war on me a couple of turns into the deal, so they basically get the tech for free. (Well...if you don't count revenge. I've a long memory in Civ, heh. A reckoning will always come, heh.
All in all, it boils down to one thing: commerce. Trade your spare luxuries for gold/turn. Trade a strat resource for a lump sum, thus giving the AI civ access to the resource for 20 turns, and that's it. Hardly enough time to do much of anything with it, and you get to line your coffers. Sell off captured workers! Hell, I should do that in my current game...I've got a TON of German slaves just sitting around...
