Yes, its very easy. Go to Administration > Content Management and you'll see a pageable grid of all feature instances in the site. Find the one you want to put on other pages and click the "Publish" link and you'll see a page showing a list of all the pages in the site with an option to publish on as many as you like.
Its also possible in the case where you want to have a feature instance appear on every page in the site and you don't want to have to have to manage it with the publishing system, you can add a control to your layout.master like this
<portal:ModuleWrapper ID="mw1" runat="server" ConfigureModuleId="x" />
replacing x with the module id of the feature instance. You can find the module id by mousing over the edit icons or links for the instance.
It will load the feature instance thereby allowing you to easily include it on every page.
Hope it helps,