Nearmap is really a fascinating set of imagery, not only can you access the latest imagery, but you can also access past imagery which means if there is clouds obscuring your view on the latest imagery, you can use older imagery instead.

However to access this previously with the slippymap plugin in JOSM you had to go to all sorts of lengths using an apache redirection to do it.

I spent some time today cooking up a patch to work round this, now you can supply a regular url that uses x=,y=,z= parameters and JOSM will load it, which should be useful beyond nearmap, however your mileage may vary :)

http://josm.openstreetmap.de/ticket/3983