Parts required.

Short length of wire and a sub miniature switch.

Note this mod will void your warrantee and may destroy your NSLU2 is you make a mistake.

Always wear antistatic protection and only try this mod if feel confidant in what you are doing.

Other power on mods can be found here NSLU2-Linux and is an adaption of Alternative 7 by jiauka.

Unclip the NSLU2 case and separate the parts.

There should be space for the switch at the bottom rear of the case.

Carefully drill a hole for the switch in the case. De-burr the hole on the inside with a larger drill bit.

Solder the wires to the switch first(you can insulate the switch now if required) then bolt it to the case. Bolt the switch so that it operates from left to right (if the NSLU2 was standing upright).

Feed the wires through the hole in the case and solder to the 5volts on the power jack and also to one of the solder pads on F1.

Slide the PCB back into the case while pulling the wires through the hole making a loop.

Clip the case back together. 

If you mount your NSLU2 vertically you may need to cut a slot in the base to take the nut from your switch.

The back of the case can be labelled with dry transfer lettering if required.

Finally test your mod. With the switch in the "on" position the NSLU2 should power up as soon as power is applied.

With the switch "off" the NSLU2 and front mounted power switch should function as normal.