As a Member, I can't even figure out a way to find my own messages without finding a message that I wrote.
I belong to this group with 933 members, GMF with 2901 members and our small group of 32.
I post to all.
The only way I can find one of my posts either here or on GMF is to remember what the post was titled (at least a key word) and search through the mass that returns.
This particular thread is pretty active so in search for the word "member", this thread is the 3rd out of 3797, for the word "search" it's 2nd of 1473.
Here's a test for you:
How can I find my message?
I can't click on "All Messages By This Member" because I can't even find the ONE I did? (Well you could but it's 23 pages down)
The VAST majority of members are lurkers, the proof is you don't have 933 messages a day.
A good thing to remember when answering these types of questions is the average end user is a novice, we should try to answer in a way that they can understand.