Josh Meyer wrote an article on how to use a custom stylesheet in a page of a SharePoint-site, without using FrontPage or modifying the site definition template set.
In his article he reveals some more tricks that I didn’t know. For example: it’s possible to use the Data View webpart (which can only be added to a page by using FrontPage), without having to unghost the page, just by creating a temporary page, open it in FrontPage, add the Data View webpart, open it in a browser, save the dwp-file (export on the context-menu of the webpart), remove the temporary page and import the dwp on any page of your site you want! Nothing fancy actually, but I just never thought of it myself.
The Data View webpart can be used to create a list-view on a page which displays data from a ‘datasource’. Since SharePoint lists can be used as a datasource as well, this is a way to display content of SharePoint-lists that do not reside in the current SharePoint-site without having to unghost pages or use third-party tools!