This post is quite old and a lot has changed: instead of automating Data Loader, have a look at automating data imports using Salesforce CLI with Powershell
The latest S#arp architecure is 1.9 something, rapidly heading towards 2.0, and all targeted at VS2010.
A couple of times now, I've needed to save in-memory ADO.NET DataTables straight to SQL Server as new tables. Its handy sometimes, if you're importing data from other sources. Nick Tompson had posted some code on the social.msdn forum to do this, and here I've stripped out the features I didn't need and adapted it to use StringBuilders:
Elmah is great. Its an error logging utility that you can drop into a .net app without changing any code. You just drop the DLL in the bin folder, and make a few web.config changes. OK, these days you can achieve the same thing with ASP.NET Health Monitoring, but Elmah is nice and easy, and the web pages it provides to inspect the error log are cool.
Log4net has lots of options and different ways it could be configured - these are notes written to myself so that I can get it working quickly.