Does anyone have a go-to source for finding new investment products (stocks or ETFS), especially programmatically?

Title says it all, pretty much. I'm working on an API application that can talk to eTrade, SeekingAlpha, etc. and grab historical and current market data for managing my watch lists. To start my list, I downloaded a master file with pretty much everything tradable on the US markets. But I don't want to download that file over and over again. I'd rather just do a search online (or, rather, have my program do it for me) that can look up products with an inception date range, download the tickers, and add them to the appropriate watch lists. I just can't find a good source for "Search By Inception Date: ". Anyone? Especially AlgoTraders or API programmers :) Thanks!