Y'know, if the situation was reversed...I can't say I wouldn't be playing Solitaire either. I sometimes think better and listen better if I'm doing some mindless activity on the computer at the same time.
And really, would any of us done any differently? People with boring instructors play on their PDAs, iPods, and laptops often. Now should they? That's another story. If it's a filibuster then what they're hearing won't apply to anything. If it's something they should vote on and they don't know the background or if one of their fellow party members is interjecting something notable, then they should pay attention. But really - congressional meetings are *boring.* I've sat through one once for my local legislators. You've got people skipping out, falling asleep, talking...no one pays attention until it's time to vote. And really, they've made up their minds long before congress convenes.