Your Dictionary.com 600+ online dictionaries in over 150 languages, plus grammar programs for 70+ languages. This is a great site which lists links to the best online dictionaries for each language including specialty dictionaries for business, medicine, culture, etc.
Travlang.com Language to language translations from a group of ten languages including German, French, Italian, Latin, and Spanish. German to Italian, French to Spanish - the possibilities are endless.
Word Reference.com Electronic dictionaries for Spanish, French, and Italian. Translations from English to the foreign language and vice versa.