This may or may not come in handy for people.
http://www.ncbi.nlm.nih.gov/Taxonomy/taxonomyhome.html/
The problem I see with it is that it only recognizes some common names.
Ball or Royal Python will give you the taxonomy page for Python regius, but crested gecko will not give you Rhacodactylus ciliatus despite the fact that there is a taxonomy page on crested friend!
One hint to get more results is to lock the search as a "token set". For example. if you search sea urchin as a complete name you wont get Strongylocentrotus purpuratus because the common name in the database is the purple sea urchin. However, if you search for "sea urchin" as a token set you do get several hits.
Some of the links on the taxonomy page for a species are helpful.
For species such as the crestie with no common name in the database you have to search using the exact scientific name--which can be a pain to spell.