There is technoport/luxinnovation/123-gonetworking in Luxembourg, but it's not focused on web startups (they accept startups from all fields). You won't get any money, but they will help you with your business plan, give you access to coaches (lawyers, sale guys, financial people, technical people...), help you create the company or to get european subsidaries, 4 months office location/servers offered for free (internet + work computers included), and much more help. (like funding, business angel connections, etc.) All startups have offices next to each other, allthough the industrial ones are located on another site.

The url is http://www.technoport.lu/. You can email me if you want more information. We started there like a month ago, and it has been great so far.

One startup that started here was jamendo (http://www.jamendo.com/en/).

Seedcamp, based in London, is similar in some ways. We were at the local event in Berlin and that was quite nice. The bad news is that the deadline for the current round was just a couple weeks back and it's only once a year.