I'd have to agree with most everyone above.
Everyone seems to imply that it depends on the situation.
If I want to take over the world, I'll stop science after computers, switch to Fanaticism (sp?), build SETI, and then take it to the AIs with 80%tax.
If I'm taking the pacifist route I'll keep up scince until I have all space stuff and fusion power then drop my scince rate to 0.
Just a side note on science, my wife the explorer (she hates building the Apollo Program) is on Prince level, 1960's and she gets 1+ techs per turn and she's on Future tech 50 something.