One of the main indicator of the financial crisis is the TED Spread. Erik Saltwell has created an iGoogle gadget that displays this information as shown below:

iGoogle via kwout

The Gadget might be found here.

A more complete explanation of TED Spread is available on this Reuters Blog post. The gist of the explanation is:

When the TED spread increases it is a sign that lenders believe the
risk of default on interbank loans is increasing. Interbank lenders
therefore demand a higher rate of interest, or accept lower returns on
safe investments such as T-bills. When the risk of banks defaults is
considered to be decreasing, the TED spread decreases.