Although I've never used a trainer, I figure rollers are easier to do longer rides on, since you're more active. My rollers have resistance too.
I didn't really do "long" rides on them though. This year I grew a pair of stones and crammed in 4-6hr rides outside once a week, all winter (rough winter in Boston this year too).
The longest I've done on the rollers was an hour and a half. I did a warmup, then 2x20 minute intervals with enough warmup, rest and cooldown time to total 1.5hrs.
Another interval session that I've been doing now closer to spring is warmup, then 3minutes on (hard, but not as hard as I can), 3minutes off for an hour....then cool down...1.5hrs total.
During warmups/rests/cooldowns, I reach for the water bottle, alternate hands, try no-handed stuff, try spinning out a few times.
For entertainment, I only have music down in the basement right now. I find the radio to be better than CD's. With a CD, when it's over, I think it acts like a psychological punctuation mark. If you're feeling lazy, you might be tempted to quit after one. The radio is better, especially around 5-8pm, when the music seems to flow non-stop, and every song is different. The speed of the music or type of music doesn't seem to bother me either.
I think the only thing you can't do on rollers is to accelerate really fast, as the belt will slip.