Long story, but I have this spreadsheet that calculates the watts required (oh, those were the days when I could generate a sustained 320 watts) to get you to the top of Grouse Mountain’s Grouse Grind trail in a given time given a person’s body mass. I keep wanting to web-expose it, but it’s too much of a pain to do it, and it wouldn’t work the way I want it to anyway.
What I’d like to have seen from Google Spreadsheets is a service that allowed me to web expose that watt-calculating functionality, perhaps embedding it within a blog post such that other people could play with it on a multi-user basis. Changes made by one person wouldn’t be permanent, and changes wouldn’t affect what other people were doing at the same time.
It’s been said many times, but people building services for the web need to think more about how they can power other applications, as opposed to driving traffic to their own re-implementation of something that already works well enough offline.