I've upgraded the way Mason simulates and performs layouts; check out the description and example on the Power Users page.  You can now map the ports of schematic item to the ports of the S-Parameters... so if you have an LNA in a SOT23-5 package, you can use that 5-pin part (with the non-RF power and ground pins) for the layout and the simulation.  The LNA just needs to have the Nodes defined as to which pins of the device map to the S-Parameter terminals.  This works well for the schematic and the simulation... but the layout is actually not quite right yet.  I have to work on mapping the power planes better, and mapping the footprints better.  Layout works okay for just microstrip and simple parts, just seem to have problems relating to mapping parts where the simulation ports is less than the number of pins on the schematic.

I've also clarified on that page how grounds can be used in TinyCad.  That's not technically a new feature, just newly documented.  I need to work on how I do RF grounds for power nets.

Also, should have some more parts libraries for download before the week is up... working on some Murata and Hittite parts.