I was doing it every time when I set on the computer desk, actually, that time I was making 1$ or less a day. Now I check 5-10 times a day just to ches if there is any problem with clicks
when i finish something big, i will check the report stats, its give me a level of supportive feelings to continue working
I use the adsense notifier plugin with Firefox, updates every 15mins. Not that I have huge numbers to report though!
Believe it or not I check my adsense winnings only once every 2-3 days depending on iff my theme has changed or if I get a huge amount of stumbles from a particular article.
I've been checking my adwords a lot too... I guess I'm more interested in how much I'm spending rather then how much I'm making...
I used to check mine about 10 times a day too, but now I only do it at the end of my work day. I figure if I invested more time into my site and less time on adsense checking then my traffic will build more and in turn my adsense money will go up.
Usually a couple times a day when I'm doing other stuff, more often if I'm in front of the computer working on my sites.