How can I see which of my Login Items is slowing down my startup time?

Recently — perhaps when I upgraded to Lion, perhaps some other time — I've noticed that OS X is not ready to go after startup as fast as it used to be.

I have a fast SSD as my only internal drive, and I used to be able to do whatever I wanted within a few seconds of logging in. Now, as my Login Items and previously-open applications are reopened, there is at least one point at which I have to wait ten or so seconds while nothing happens.

It seems to me that Login Items are launched (somewhat) serially and not (entirely) in parallel. From that assumption I conclude that at least one of my Login Items is holding up the rest of the queue.

So my question: Is there a way for me to log the startup process and look at the log to see which app is hanging the queue?

You can see the start time of the individual processes in Terminal (ps aux). This may give you an indication about relative start time and any delays occuring.

If you go to System Preferences » Users & Groups » Login Items, there is a list of items to automatically open.

I have not been able, in Lion, to drag items to arbitrary positions in the list, as I remember being able to do in earlier versions of OS X. One can, however, drag items to the bottom of the list.

So it would appear that you could one by one drag everything that appears in your list before Alfred to the bottom of the list, thus launching Alfred first.