It's best just to leave a big gap between yourself and the car in front of you and drive at a slower speed. Your average speed will probably end up being the same anyway as if you had continually accelerated and braked abruptly, but it would be less frustrating.
Yes, leave room in front but also have some consideration for the person behind you. If I can't (or am not willing to) pass, I try to leave as much room behind me while staying a safe distance from the vehicle in front of me as possible.
You slow down a bit so the one who drives behind you gradually drives closer until he notices that you slowed down. Then he realizes he must slow down as well, making space between you and him, and the safe distance propagates further backwards.
However, the road is full of people who are more concerned about watching the scenery pass, carrying on a phone conversation or looking for landmarks in unfamiliar territory. This is perfectly fine until traffic starts backing up behind them. As cars are added or lanes reduced away, a jam becomes increasingly imminent. And jams are just the extreme example. Patient motorists driving slowly behind distracted ones still have their goals deferred.
What I'm saying is, haste is relative. Slow down if you want to--it's a free country. Just have some consideration for the people behind you.