As I understand it, the Great Depression was caused because of overspeculation.  This overspeculation was made possible by overlending (history seems to repeat itself, eh?)...

The causes of the Great Depression were a bit more complex than "overspeculation".  The government had to take some extraordinary actions to restore confidence in the monetary system back then, just as it has had to take extraordinary actions in the past few weeks.  Your characterization of the issue does not explain why "overspeculation" happened to occur just at that point in time and not others.  Nor does it explain why we have not experienced such rampant "overspeculation" until just recently.  One important restriction that restored confidence historically was Roosevelt's forced separation between commercial banks and lending institutions. 

That separation was ended in 1999, when Phil Gramm led the deregulation charge in Congress, egged on by Greenspan.  Clinton was very taken with Greenspan's deregulation mania, as were many other so-called "centrist" Democrats.  So he signed Gramm's bill.  Then Greenspan convinced Bush to pressure the SEC into further deregulation in 2002, which is what led directly to the recent monetary crisis.  In Greenspan's imagination, bankers would act responsibly and the markets would "self-regulate".  He had deluded himself into thinking that the markets  would be even safer if the government were not looking over their shoulder.  After that, there was a stampede of greed to create mortgage-bundle securities of bad debt that could be traded around like hot potatoes.  Eventually, some of the big players got overwhelmed by the sheer number of these hot potatoes, and the bubble burst.  It is true that government action led to the crisis, but the government action that led to it was market deregulation, a cause celebre of Republicans and centrist Democrats.

The overlending happened because banks did not have an objective standard of value from which to judge how much they could safely and rationally lend.  The reason?  Because instead of reserves based on an objective standard of value (gold!), the government had been artifically inflating their reserves with paper hoping to fuel a never-ending boom of liquidity and growth.  Instead they got us the Great Depression...

But you do understand that the US had suffered bad recessions and depressions while still on the gold standard, don't you?  The gold standard was not exactly an ideal tool for monetary control, and the markets really did need more credit to meet the needs of economic growth.  What you do not acknowledge here is that the US lived through an incredibly long period of relative economic stability until just recently.  And none of that period had a monetary system backed by gold.  Gold was not the solution to economic stability, and it has not been needed to protect our economic system for over 70 years.

The current crisis was likewise caused by too much credit, artifically too much credit created at the hands of a bizarre "orgy" between big business and big government.

Yes, but that was brought on by a foolish radical experiment in DEregulation.

... The problem isn't that there was not enough oversight or regulation, the problem is that there was too much incest.  A free market unhampered by the contrivances of interventionist government and opportunistic, greedy businessmen would not have created such a crisis because it would have had a market-determined amount of credit at a market-determined price.

False.  Unregulated markets only address short term needs and desires.  Government regulation is needed to guarantee long term stability.  You would pour gasoline on a fire.