An update to the original MageTaxi for Classic. Theoretically, it should work in the latest expansion as well, but I stopped playing that ages ago and not going to reinstall it just to test it.
DISCLAIMER: I do not currently have a mage (either faction) with portals learned, so if there is an issue please let me know right away.
Features
Automatically detects for Alliance/Horde
Easy one-button advertising
Automatic Trade channel detection
Automatically disables ports the character hasn't learned yet
Custom pricing
Usage
/magetaxi OR /mtaxi to open window
The Buttons
Advertise Button: Posts whatever message is in the text box to Trade - City channel
LFM: After receiving a port request, press this to advertise for additional players
Last Call: Final offer for additional players
Portal Button (bottom center): Click to cast the portal spell selected
Special Notes
By design, this will not work outside of a city and I have no plans to change this.