Hostelguide.de - very comprehensive and up to date hostel-directory on the web, free and noncommercial.

Berlin Hotels - The Berlin Hotels Travel Guide - Discounts hotels up to 75% with guaranteed lowest rates.

Munich Hotels - The Munich Hotels Travel Guide - Discounts hotels up to 75% with guaranteed lowest rates.

Hamburg Hotels - The Hamburg Hotels Travel Guide - Discounts hotels up to 75% with guaranteed lowest rates.

Frankfurt Hotels - The Frankfurt Hotels Travel Guide - Discounts hotels up to 75% with guaranteed lowest rates.