Morse Code and the Phonetic Alphabets - http://www.soton.ac.uk/~scp93ch/morse
Includes a Java Morse Code Translator, CGI Morse Code Translator, a listing of the Morse code and the more common phonetic alphabets.
Oxford English Dictionary (OED) - http://www.kcls.org/erout/goto.cfm?f=oed&d=60
Definitions, pronunciations, and word histories. Usage of modern and historical words traced through 2.5 million quotations.
Oxford Reference Online - http://www.kcls.org/erout/goto.cfm?f=oro&d=61
Language and subject dictionaries and subject reference works - containing well over 60,000 pages - into a single cross-searchable resource.
yourDictionary.com - http://www.yourdictionary.com/
A comprehensive listing of dictionaries including Merriam-Webster, Multilingual Dictionaries, Specialty English Dictionaries, Thesauri and Other Vocabulary Aids, Language Identifiers and Guessers, An Index of Dictionary Indices, A Web of On-line Grammars, and A Web of Linguistic Fun.