http://weblogs.asp.net/bsimser/archive/2004/12/26/332467.aspx 

This post outlines how to consume web services within a data view web part without writing any code at all (well, ok.. XSLT might be considered code.. but at least you don't have to break out Visual Studio :-) )

NOTE: He is using frontpage to accomplish this... make sure that you heed his advice on creating the part on a page that is not one of your default pages (as it will unghost it).. You can build the parts in a dev environment and then export them and import them onto the pages that you want to put them on in production. this allows you to work around the nasty problem Frontpage has with un-ghosting pages

Hope that helps, I have had more than one person ask me about Web Services in SharePoint !