http://blogs.tamtam.nl/mart/HowToSetACustomDefaultMasterpageForAllSiteDefinitionsInWSS3.aspx
nice article.......without any Deployment of MasterPage.........
if u want to Create a master page using Features......then check this link......
(heathersolomon MVP sharepoint) Nice article
http://www.heathersolomon.com/blog/articles/servermstpageforsitecollect_feature.aspx
