Warning! Graphs and del.icio.us references ahead! Non-del.icio.us nerds beware! Webmaster tool Grafolicious makes a neat-o line graph of del.icio.us user bookmark frequency of a web site over time.

As waves travel, they set up patterns of disturbance. The amplitude of a wave is its maximum disturbance from rest (its undisturbed position). Key fact It is important to note that the amplitude is ...