Panasonic Fluorescent Bulbs
So... according to Panasonic, Home Hardware carries these bulbs (regardless of what the packaging shouts about "Gen IV" etc, they're known within Panasonic as "EFA" bulbs). But before you go running down to your local branch, phone ahead. My closest store bought stacks of them when they first came out but they didn't sell well. He can order them in but they're not necessarily in stock just yet.
Also... I mentioned to the person I talked to at Panasonic, Canada, that the 23W bulb was a little too dim, that a brighter one would be nice. She said their supplier had chosen not to produce anything brighter. Perhaps there's some technical problem still to be overcome.
And... if you do go in for replacing your bulbs at home with any kind of fluroescent bulbs, you should be aware that they contain mercury and should really be recycled in some other way than through the trash (unless of course you want mercury in your local water table some decades from now). Not that any municipality that I know of has that kind of recycling infrastructure in place yet, but it's something that somebody should be doing something about.