Looks like according to microsoft, silverlite (their version of flash) wont be coming to the iphone but might be comming to the g phone aka g1.
hey microsoft how about working on silverlite/flash for your own operating system first. If you know where to look you can find a flash cab file to install and will give you basic access to flash site. But microft should worry about there own first

http://www.fiercewireless.com/story/microsoft-no-silverlight-iphone-maybe-g1/2008-10-14