Baseball Nation Simulation League
Player pages allow teams to enter roster moves and option decisions directly through the interface. Click on a player on your roster, then "actions" on the left menu.
Transactions menu has a list of trades, waivers, and general roster moves (in case anyone cares).
Team pages have a list of that team's trades. Will import past trades at some point.
Players menu tab now has dropdowns for Rule 5 Eligibles and Free Agents among others.
UPCOMING: Payment list on team page, sortable/searchable/downloadable player lists