Just took my first real trip on my 06 VFR and needed a power port for charging cell, camera, etc. I had recently put a $29 battery tender / plug on my battery with the lead just barely sticking out at the seat release lock. The tenders come with a second lead with alligator clips- which is what I used for the power port...
Cut off the alligator clips right behind them (note polarity) thereby reusing the inline fuse. I bought a female cigarette socket with about 6" leads at the parts store for under $3.00. After slipping on some shrink tubing, I soldered up the wires- NOTE: THE SOLDERED CONNECTION IS DONE IN REVERSE OF INDICATED POLARITY!!! This is because the alligator extension piece socket end is identical to the one already hard-wired to the battery, yet they fit together, but their indicated polarity is reversed when doing so! If you understood that, you will have a setup with the fuse on the negative line (I'm no electrician, but I don't see why this would not still protect the circuit in a DC system, like here: Add In-line Fuse to ACR Battery Negative Connection - Resources - Blue Sea Systems )
Double check your set up with a meter. The center pin on the cigarette socket is positive and the outer housing negative. The fuse supplied in the Battery Tender extension is 7.5 amps and should be adequate for anything you would be plugging in.
Any ways it worked great! The small inverter I took along will easily run a laptop and has its own USB output for charging my camera.
With some shrink tubing, elect tape, and the 12v socket, the whole project cost about $5.50 and took about 15 minutes to complete.
I used the port after the days riding, but it could easily be adapted to use while riding. Cheers!