HouseMan lets you create a list of known players (across all accounts and all servers*) and then add those players to your house guest or house storage list by clicking some checkboxes.
The state (guest access, storage access) for each known player is saved per account and server, so if you give storage access to "Some Player" from Account A, but only give him guest access from Account B, the plugin will remember that.

Currently there is no support for importing names or even the guest/storage privilege states from "@house guest list", but I have some ideas how to do that and will probably get the code done by next weekend.

Download link (as usual) on http://ac.ranta.info/DecalDev

Bug reports and suggestions are welcome.

*: If there are people who really have houses on more than 1 server and want to use this plugin, please let me know and I will change the code to save the known players etc per server.

Known bug: the plugin will throw an uncaught exception if you use it after switching a char without restarting the client. If that happens, click "continue" on the exception message that should pop up, then click abort in the plugin. You need to close the client before you can use HouseMan again.
I have a fix here, but it's a tad late and I am tired, so I will release a new version tomorrow. Sorry for the inconvenience.