Just a quick note on this - I'm currently working the confirmation side of things but at the present time Mastercoin transactions will only show up in the Masterchest.info block explorer once they have been confirmed by the bitcoin network in at least one block.  The scan time is every 5 minutes, so the worst case you should be looking at for a transaction to show up is 15 minutes (avg 10 minute block time + 5 minutes between scans).  Thanks

EDIT: And FYI transactions sent via multisig are pulled into the 'transactions' table but not 'transactions_processed' (so won't show up in the web interface) as I'm still testing that functionality.