A tool that is integrated into Visual Studio that people often forget about is the Immediate Window. The Immediate Window will allow you to evaluate expressions while debugging. For example, rather than using the visual tool to examine the item within a collection, you can just issue a command in the Immediate Window. Such as:

Intellisense is also supported:

You can also do intermediate calculations:

But sadly, no query (LINQ) expressions:

By default, this window should show up when running in deug mode. If not, the default keyboard shortcut (for 2008) is Control-D,I. Joe left a comment that Control-Alt-I is also valid, which works in 2005.
For non Express users, also check out the Command Window for more goodness.
Added:
Also, check out this post about the Watch Window at Von#.



February 27th, 2008 at 10:29 pm
Immediate Window - A forgotten tool…
You’ve been kicked (a good thing) - Trackback from DotNetKicks.com…
February 29th, 2008 at 2:50 am
Whats funny is that I just discovered this myself about two days ago (Im a fairly recent .net convert). Good job spreading the word, absolutely indispensable tool.
February 29th, 2008 at 3:46 am
Ctrl + Alt + I brings it up too.
Ctrl + Alt + A should be your next post — <3 the command window
February 29th, 2008 at 2:04 pm
[...] Immediate Window - A Forgotten Tool (null) [...]
February 29th, 2008 at 2:49 pm
You can make assignments in the immediate window as well:
words.Count
1
words.Add(new Word())
words.Count
2
February 29th, 2008 at 5:47 pm
Good point Tim B, thanks.
March 3rd, 2008 at 7:24 pm
[...] Immediate Window - A forgotten tool [...]
March 12th, 2008 at 10:17 pm
[...] Command Window, like the Immediate Window, can be one of those tools that a developer can find to be an invaluable aid and time saver. As the [...]
March 28th, 2008 at 11:03 am
I’ve lived by the immediate window for years. But it drives me mad that Visual Studio hides it so effectively. I spend ages looking through obscure debug windows lists, but can never find it (C# hides it away, whereas VB.Net shows it!)
Thanks Joe for the Ctrl-Alt-I combination!
June 20th, 2008 at 7:42 am
I always wondered what that windows was all about. Now I know. Thanks.