Yahoo, Go and others battle for small businesses.

Yahoo_s shopping site can put small businesses online for as little as $100 a month. Yesterday_s online malls - random collections of stores that shared a single online entryway but nothing more - have given way to soup-to-nuts e-commerce machines. And the portals, such as Yahoo, Lycos, Go Network and Excite, are leading the charge to bring small merchants online, offering store-building software, back-end tracking tools and a host of cross-promotional opportunities to tie everything together.