Does Twitter "Own" 140 Characters?

I'm doing a startup and one of the fields will be a space for a short blurb of text - right now it's 100 characters (and counts down a la Twitter) but I've been thinking it may make sense to make it 140 characters... people are used to that length at this point, and it'd make sharing content from Twitter on my site easier.

However, I don't want to draw comparisons to Twitter (even in the sense that it's just one component of the site) because I'm not trying to compete with them.

Can apps beside Twitter use the 140 character limit without people immediately thinking of Twitter, or of your site as a secondary service?