Hi there
Well you could try a site I created for exactly that sort of thing

I created it to help me lose weight by recording what I eat, my weight, exercise, sleep, and even how much coke I drink (i.e. too much!)
It's called
Graphomatic and it lets you record and graph anything you want.
You can see some of the things I record on my
public dashboard. You can choose what is public and what's private (there are a few graphs that you won't find on my public dashboard).
You can even embed individual graphs on web-pages (and I'm working on a Facebook app to do the same on your profile page), for example this is my weight graph...
There are still a few rough edges, and I'm actively working on it, so if you do use it, let me know how you get on, what works, what doesn't, if you have any problems with anything.
I'm trying to make it as easy to use as possible, so it would be great to have some feedback from other people about features they would like to see.
Unfortunately you cannot get the data off the Wii and out of Wii Fit unfortunately. I was really hoping that Wii Fit Plus would add this, but sadly that feature is still absent. I think it's a really big omission by Nintendo, and a missed opportunity.
There are people trying to work out how to get the data out, but it appears to be encrypted

I just enter the numbers manually as it only takes a moment to do. Having it on the web makes it easy for me to use at home, at work and even out and about if you have a smart phone or an ipod.