All Free Dictionaries Project
Online project to build free translating dictionaries (e.g. English to Spanish) by allowing individuals to add and correct entries. Several dozen languages represented so far. Dictionaries can be searched online or downloaded. Includes links to other free dictionary sites.
PONS.eu - The Language Portal
Free online searchable dictionaries for many different language combinations (English to/from Spanish, German, Polish, Russian, etc.; German to/from Spanish, Italian, Turkish, and many more). Free online computer translation between more than a dozen languages. Vocabulary Trainer lets you quiz yourself on word translations. German/English Visual Dictionary lets you learn vocabulary through pictures (geography, the body, etc.).