General
Online Conversion
The World Clock - Time Zones
Dictionaries
Logos dictionary - A freely-accessible multilingual dictionary.
Morfix - Hebrew-English, English-Hebrew dictionary. Serves also as a search engine.
OneLook - Retrieves definitions and translations of words by using web-based dictionaries.
YourDictionary - Dictionaries in English and hundreds of other languages. Includes also specialized dictionaries, thesauri and glossaries.
Encyclopedias
Bartleby - Reference resources
Wikipedia
Scientific writing
ASHS Style manual - A useful guide for authors submitting papers to either HortScience or the Journal of the American Society for Horticultural Science (Publications of the American Society for Horticultural Science).
Journal abbreviation resources on the web
List of useful resources - compiled by the University of Illinois.
National Library of Medicine Catalog (NCBI - National Center for Biotechnology Information)