Today I am got started as an eleven day challenge, some key guys took up the challenge and managed to launch "Twitter-like" site in just 11 days. This I think is a good example of what investors keep an eye on, what's the barrier of entry for somebody to do something others have already done. Now of course in the internet world of today, you do have to create enough momentum to build a user base quickly and be able to manage and keep your user base. I personally don't know how many "Twitter-like" sites are needed? I do see a point if you think local country users vs. global use. Also when you know that in many countries people prefer a local base using the local language in question. But feel free to take a look, I have user tlidforss here on http://today.im as on other micro-blogging sites.