I often see the argument along the lines of.

"We hate Microsoft and Open Office has the best market share. We should stick it to them by only sending our documents out in ODF. Then when people get it they have to download OO to read it. Muhahahaha!"

This argument is wrong because MS users will just delete your document. Firstly because they don't want to download it and even if they did they probably don't have install rights from IT. Secondly, on principle because your a dick.

However, why not just use PDF instead (although not open, it is an ISO standard and most if not all office users can open it on their PC).