Real World Connections:

Mendeleev's Periodic Table, 1869
Check out Mendeleev's original periodic table at this site:
http://periodic.lanl.gov/mendeleev.htm

EnvironmentalChemistry.com: Periodic Table of the Elements.
Comprehensive data on elements including scores of properties, element names in many languages and most known nuclides is provided by this periodic table. In addition environmental and chemistry articles round out this site.
http://environmentalchemistry.com/yogi/periodic/

WebElements
Visit WebElements, a site that claims to be the first periodic table on the WWW. This web site features a printable version of the periodic table.
http://www.webelements.com