The data represents one month (May, 2005) of internal USA air traffic composed of 2649 airports connected by 13106 links. .The file is in the Complex Networks Package format and can be loaded with GraphLoadFromFile method:
Graph = GraphLoadFromFile('FLGraph_2005_05');
The graph is not weighted, but let me know if you need weights - I can share the weighted graphs based on actual traffic between the nodes (number of flights, passengers, physical distance, cargo or mail - whatever you want). Monthly data since 1990 is also available (at this point, you are probably wondering in how the 9/11 attack influenced the air traffic network).
Here, you can get the network, representing Wikipedia structure in Italian. This data also comes from May 2005 and contains graph of terms (plain Wiki articles, not user pages, talks, etc) ) in Italian Wikipedia where links represent references of other articles. The Italian Wikipedia categories are arranged in the same way here.
Similarly the the other data, these files can be imported into MatLab with my package in the following way: Graph = GraphLoadFromFile('itwiki.wiki');
If you need an examples of what can be done with this kind of data, I'd suggest my own paper recently published in PRE or, perhaps, visiting The Wikipedia Analysis Project. Another option, is playing a bit with the Clusterizer Application entirely based on the similar data.