A Girl from Japanema?

I've been going back and forth on the issue, but I've decided that even though my Japanese skills aren't what they used to be (which isn't saying a whole lot), my daughter needs to learn her some of it. I don't quite know how to go about it though. I mean, she knows about 30 words of English (which is to say she can say 30 words - she knows more than she lets on), so is it really worthwhile to start speaking to her in Japanese? I've done it a bit so far and I get a nice little chuckle, but I think she's more laughing at the jibberish her dad is saying than what I'm talking about. What do you more bilingual people out there say? I know that speaking multiple languages is desirable, and not just because you can get a job in that country or because it's a nice party trick. It can help with the development of higher levels of thinking and it can help with comprehension among other things. Of course, this isn't truly a multilingual house, unless you count Sorroisms as a different language, as my wife sometimes does. (Sorroisms tend to be obscure pop culture references and archaic words like hogshead, chain [a length of measurement], sundry, and so on.) Nevertheless, it seems like it would be valuable, and that's in large part because I've been told so by everyone for quite some time. I know that bilingual children can pick up other languages much quicker than people who just knew one language growing up, and that can't be a bad thing.
Of course, another issue is how useful Japanese actually is. Because I quite like Japan and would like it to have a permanent place on my SkyMiles Reward Ticket Redemption Destination Rotation, if she ever goes with us (which would be the objective when she gets old enough to sit in coach with her siblings while we live the high life on BusinessElite reward tickets), so it would be useful for her to be able to do things like say hi and read the different types of soda they have in the vending machines. It would also be useful if she decides to ever spend some time there alone as an adult and/or take a job where learning Japanese would be helpful (the computer and consumer electronics industries come to mind). It would also help her if she went another direction, like allow Dora the Explorer to convert her to Spanish. Finally, she could understand the Miyazaki movies in all their Japanese glory. It's definitely going to kind of happen, the question is how much and when should I push it. Cheeth, as the resident translator, do you have any suggestions?