netmeg, let's make an exception, in this thread only, and allow mention of tools that can be used
'k, I like this one:
Run your site through that; then you can sort the results by load order, by file size, by URL, or by load time. Real easy to find the resource hogs fast.
At the top is the TL:DR - your overall performance grade. I just ran WebmasterWorld through it and despite 106 requests, it scored at 93/100 overall, with a load time of 2.23 seconds. Of course, we don't have a lot of images here either; that makes a difference.
Then go the 'waterfall' and mouse over the measurement - you'll get the time in milliseconds for each resource there - DNS, connect, send, wait, receive, etc. Got slow DNS issues? It should show up here.
Back up above the waterfall, you'll see tabs that include performance (get a "grade" for possibility of performance optimization), Page Analysis for specific URLs, and if you've run your site through it more than once, a history.
Obviously since I didn't oversee creation of the tool, I wouldn't consider it flawless (nor is Google's tool) but I think this one can at least point you in the direction of areas of concern.
I also like [urivalet.com
...] (created by a WebmasterWorld member that isn't me)
This one doesn't grade you on performance, it just lists everything that loads.
I never use just one tool, I test stuff in everything I can find.