Developer console: Total Requests Limit Exceeded  error

When I load the developer console, I get a "Total Requests Limit Exceeded" error.

Its because you've ran into your API Limit for the 24-period.

                                            
   Check this: setup àsystem overview

Solution:

You API Usage will be on the top right. If you are at your maximum, I suggest calling Salesforce-Support immediately, and ask to get your API Limits increased temporarily. SF-Support is generally friendly and will usually grant the request. (If you have 5,000 API calls/day, ask for an increase to 10,000 temporarily).

Screen shot of System Overview Link: