listtransactions will list transactions only involved with me?
"listtransactions" will list all the transactions associated with your specific bitcoin wallet.  The "All Accounts" business, I believe, has to do with the various addresses someone could have withing a single wallet.  

For example, I have an address where I receive donations, and a different address where I receive mining payouts.  by default "listtransactions" will list all my transactions from both addresses, however, I could specify one of my addresses and it would list only those transactions.  It's an easy way to get more granularity in the lists and organize your data better.