Yesterday I was doing another "Knowledge Transfer" session and before I started walking through some code in a debugging session, I took a brief detour to show the team how I recommend disabling the "ping" functionality in IIS for your application pool. Note that this recommendation only applies to development environments -- please don't disable this on your Test or Production environments.
In case you aren't aware of it, IIS monitors the health of the worker process for your application pool to ensure that it is responding to requests. If the worker process doesn't respond in a timely fashion, IIS summarily terminates the process. Note that this is the default behavior in IIS 7 (Windows Server 2008).
However, if you are stepping through a Web request in the debugger (presumably in an isolated environment where you aren't affecting other team members), then it is mighty inconvenient to have IIS terminate the process you are debugging.
Consequently, one of the first things I try to remember to do after creating a new application pool -- e.g. creating a new Web application in Microsoft Office SharePoint Server (MOSS) 2007 -- is to change the Ping Enabled setting to False.
I just did a quick Bing search and found the following resources (in case you want more info or detailed steps):