That's always confused me, too. There seems to be too much overlap in the use of the terms. I mean, an 18 mm lens on a film camera would be a "super-wide," but on a typical Nikon or Canon digital SLR with a 1.5X or 1.6X crop factor, it would become the same as a 27-28 mm lens, which is merely "wide." It depends on where you want to draw the line between classes, but it also depends on what camera you are putting the lens on, too.

You have to ignore the terms, then, and just learn what the actual numbers mean. Choose your lens by the focal lengths that you want.

See http://www.flickr.com/photos/samfeinstein/476181737/ and read the commentary under the image. This will teach you all you need to know about choosing the focal length or range that you want.

http://www.flickr.com/photos/samfeinstein/1245831147/ is similar.

See also: http://support.nikontech.com/cgi-bin/nikonusa.cfg/php/enduser/std_adp.php?p_faqid=4606&p_created=1054912490&p_sid=CB8iAcGi&p_accessibility=0&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9NSZwX3Byb2RzPTgxJnBfY2F0cz0xNzcmcF9wdj0xLjgxJnBfY3Y9MS4xNzcmcF9zZWFyY2hfdHlwZT1hbnN3ZXJzLnNlYXJjaF9ubCZwX3BhZ2U9MSZwX3NlYXJjaF90ZXh0PWRlcHRoIG9mIGZpZWxk&p_li=&p_topview=1