Those who missed my talk about iText at Devoxx, also missed a cool demo about Geomajas, but no problem: why not test the demo yourself?
When you open this URL in your browser, you get a map of the world. You can zoom in on any part, for instance: on Northern America:

If you click "My Map", you can add or remove layers. You could replace the OpenStreetMap layer with the Google Maps layer. I added the "Tiles@Home" layer, but I made it slighly transparent.

You can also search for a specific place. For instance: I want to visit the Aquirium of the Bay, so I search for Pier 39 in San Francisco:

Did you notice the print button in the upper right corner? Let's click on that button:

We get a print dialog we can use to customize our map, and as soon as we press "Print", a PDF is being generated:

You may wonder: why should we use Geomajas if we can use OpenStreetMap? Well, Geomajas allows you to join different layers from different sources, including your own GIS databases. Geomajas isn't limited to read-only operations, you can also edit layers, add shapes,... If I understand correctly, it's a front-end web GUI to insert data into your back-end Geographic Information System. And if creating maps in PDF is part of your requirements, please contact us, because we're kind of eager to improve the print module with OCG (but we need sponsors to do that).