Some 8 to 10 years ago I experimented with a 2 innings ODI format in my local team - Young Strikers Cricket Club. This is also mentioned on my blog in another blog post.
We played a number of 2 innings ODI although that was with a tennis ball wrapped in tape.
And today , September 11 2009 , I have just heard from a news channel that Tendulkar has proposed a new ODI format.
I searched around the web and found one more site that proposed the same but the timestamp isnt clear and to me.