So what is the deal with ASP.NET web parts and SharePoint web parts?

Well, glad you asked.   I am not an authoritative source but thought I would document a few links since an associate of mine was asking and I was curious.

Resources

Sharepoint Web Parts Overview 
http://msdn2.microsoft.com/en-us/library/ms432401.aspx

Windows SharePoint Services Web Part Infrastructure
http://msdn2.microsoft.com/en-us/library/ms415560.aspx

Walkthrough: Creating a Basic SharePoint Web Part
http://msdn2.microsoft.com/en-us/library/ms452873.aspx

Walkthrough: Creating Connectable SharePoint Web Parts
http://msdn2.microsoft.com/en-us/library/ms469765.aspx

Creating Web Parts in Windows SharePoint Services 
http://msdn2.microsoft.com/en-us/library/ms367238.aspx

Working with the Windows SharePoint Services WebPart Class 
http://msdn2.microsoft.com/en-us/library/ms473203.aspx

Channel 9 Video: Building ASP.NET Web Parts for Windows SharePoint Services 3.0
http://channel9.msdn.com/ShowPost.aspx?PostID=192071

15 Seconds: Building Web Parts for Windows SharePoint Services 3.0
http://15seconds.com/issue/060824.htm

15 Seconds: Building an ASP.NET 2.0 Web Part for Deployment to WSS V3.0 and MOSS 2007 - Part 1
http://15seconds.com/issue/060914.htm

Scott Guthrie (MSFT): Writing Custom Web Parts for SharePoint 2007
http://weblogs.asp.net/scottgu/archive/2006/09/02/Writing-Custom-Web-Parts-for-SharePoint-2007.aspx

Mark Kruger (SharePoint MVP): Great resource link site for almost everything Sharepoint
http://www.sharepointblogs.com/mkruger/archive/2006/05/25/7570.aspx

If anyone has any great resources on comparisons between the two let me know I would be interested ...