I've been playing with VS2010 for a couple of days now, and I just recently stumbled upon an awesome features that every Dev will love: "Call Hierarchy".
In simple words, you can now view where your methods/properties are being called from. Now, you might say, "We've had that for a while, its called 'Find usages'", Well, this is better: You can actually view and go through the call tree graph WITHOUT having to be in debug mode. As Borat would say: "Itzanice!" Scott Gu has a really nice post about it, go see it.
Playing around with it, I noticed that ReSharper also has its own implementation of it: “Call Tracking”. And, it is actually better than the one with VS2010. So, if you have ReSharper, go to a method and do Ctrl+Shit+Alt+A , then select “Incoming Calls”. A new window will open up showing all callers to this functions and the tree graph. It’s so cool!
You might have also noticed that you can select “Outgoing Calls” which is the exact opposite of viewing all the callers, it’s a “Go to definition” on steroids!
As ReSharper puts it, Call Tracking is “an all-out Find Usages and Go To Declaration”. Go check out their post about it to find out more details.