Interesting! I've been tinkering with something similar myself, though not quite as focused on 'mobile' and the SMS-inspired size limit.
One other site in the same vein is 'Factolex' – http://en.factolex.com/. (I saw one other tweet-sized 'reference' site in the last year or so but can't find the link.)
What are your hopes for Stubia? For example, do you prefer people make entries in an 'authoritative' or a 'whimsical' tone?
The basic goal of the site is to have a place where people can create content that would otherwise be deleted by Wikipedia; no concerns about notoriety and no pressure to expand articles. I don't really have any plans to impose any rules on the site, for now I want to focus on collecting the long-tail of articles that doesn’t exist on the web.
There is also a micro-blogging component to the site. Depending on the context attached to the article a series of buttons appear on the article page(By default just "Love" & "Hate", I left out selecting contexts for simplicity and data quality concerns), clicking on them creates a post on your profile: http://www.stubia.com/@abe
Let me know if you find that other link, I would be interested in taking a look at it.
Capturing knowledge that doesn't fit Wikipedia is one of my goals as well.
My hunch is that because such topics may be more obscure, a little more space/context, and some new modes of search/display, will prove helpful for readers/contributors.
