Took a minor detour from what I had planned and implemented support for importing/rebroadcasting offline transactions as implemented by piotr:
https://forum.bitcoin.org/index.php?topic=28278.0

Everyone (not just registered users) can upload an offline transaction and it gets broadcast to the network every half hour until it makes it into a block.
(With a limit of 100 tries in case the transaction is just bogus / will never be accepted)

http://webtc.interesthings.de/transactions/import