Either you're a Jim Carrey fan or you're not -- I'm not really sure if there is room for something in between. I fall strongly in the "not" category mostly because he is of the breed of manic comedians who often employ the serious-movie-calls-for-sincere-voice/face acting that cries out for A Golden Globe.
That being established, it pains me to see Carrey in commercials for Yes Man -- the movie based on Danny Wallace's book of the same name. I absolutely love this book -- in fact I wrote about Yes Man after reading it in 2006.
The premise of Yes Man -- and I suggest that you order it from Amazon right this moment -- is, that for about six months (the remainder of his year) Wallace decides to say "yes" to any opportunity presented to him. It's part travelogue, part memoir and part self-help. It's not heavy-handed at all in its self-help ways and I appreciated that greatly. It manages to be inspirational and funny -- so much so that I found myself, on our plane flight home, crying with laughter the moment one odd picture suddenly makes complete sense.
While Wallace uses saying "yes" as his gimmick for his book, it was far from being a gimmicky book. There are no magic spells or motivational speakers that make Wallace say "yes." Even if Jim Carrey's Yes Man sort of looks like a 2008 version of Liar, Liar, please don't let that discourage you from reading Wallace's book. It's such a quick, fun read.
 The patron saint of this group is Robin Williams -- who I find far far less tolerable than Jim Carrey.