freelancers.com ,elance etc ask for portfolio web related

My basic idea here is for starting a software company

Well the people giving projects at freelancers and such sites basically ask for a portfolio, i have been in this field professionally for about five years working but really don't have any substantial freelance thing to show as my skill.

What to show them? how to get out of this question . i have been esquire about some projects but most of the question is that can you send us your portfolio . i am trying to build something out of this from small.

How many web applications they expect to see from me ? If i build something then what should i build in small time say 15 days that would click in scenario and get me pass the first hurdle? What do you people recommend ?

If you contribute on a site such as github, your github account alone would stand as a portfolio. I can see it being very difficult in sharing a portfolio if you're a programmer, often you work for companies on projects in which you are not allowed to share many details. Also a lot, if not all, your work is on the backend of something. As you don't want to paste up a bunch of code as your "portfolio" since this is just absurd, you could try starting out with github and then going from there. You can use it to host your own project, and your future clients can kind of see what you design. Alternatively, there are many projects there that need help. If you were to help out on some of the larger projects, it would still show up as work you've done.

As for portfolios for programmers, that's pretty much all I can think of.

You can show your open source contributions to them so that they can analyse you based on the code which you contributed ................Also in odesk take as many tests as possible so that you will be getting score and based on that also people will select freelancers.......most importantly and i prefer contributing to open source which gets you lots and lots of contacts in the market.