Some of us like to commute :P And continuing the analogy, people choose the bus for saving money (implying you're using your money on other things), or helping the environment, or it's more convenient so you don't have to find parking, etc. I'd say most of those reasons with a bit of adaption could be applied to why people use OO too.

On the other hand, bus systems can be frustrating and slow, and they may not drop you off exactly where you want to be...which also could apply to OO.

And haven't messed with it much, but it seems like Calc can do most things Excel does, albeit using some very useful statistical plugins (can't find the link at the moment) it exceeds some of Excel's capabilities.

If OO ever implements this (wiki last update mid-2007): http://wiki.services.openoffice.org/wiki/Statistical_Data_Analysis_Tool then it'll be way past Excel and halfway to statistical software like SPSS. Wish I knew how to implement, as I'd love to have that built in...

For a while, I used OO mostly to assuage my guilt at using Office illicitly.

Then I found out that OO has a major advantage: internationalization for countries that just aren't within Microsoft's marketing strategy. As a (foreign) person working in Mongolia, the relatively basic addition of international spelling packs, particularly for Mongolian, has been a lifesaver - and though I haven't used it, there's a Mongolian localization for the entire suite that I think would remove a significant utilization barrier here. It's hard enough teaching someone how to click versus double-click; throw in a menu system in an incomprehensible language and you might as well give up at anything but the most basic data entry.

For this alone I'll use OO over Office.

And from a helping standpoint, I haven't done much beyond web-based DB-driven apps for a while, but with Ubuntu's relatively painless localization process, I'm trying to help out by doing Mongolian localization for the OS myself.

There are places for everyone to help - it may not be exciting but I figure you should pay it back in somehow.