Ebay search for "jtag cable linksys" gave at least one hit.

For your board look at the front edge for a 2x6 block, it will be fairly obvious 12-pin location. They will either have open holes or be filled with solder.  For solder removal I clamp board upright and put solder-sucker in one hand against a hole from one side.  Then touch the point of the iron to the same point from other side.  Hit the trigger on the solder-remover and POP all the solder goes into the vacuum and you have a nice clean hole.  Repeat 11 more time and it's ready for a header.

Takes me less than 5 minutes now.

I am not bricked, but want to revert to WhiteRussian and can't seem to TFTP my WRT54GL at boot either.  And can't seem to find how to set boot_wait on Kamikaze.  Can anyone help?

You can ssh to the router (192.168.1.1) and then use the 'nvram set boot_wait=on' command followed by 'nvram commit'.  I'd recommend checking it first with 'nvram show'.

Ah, fake out.  I'd read that Kamikaze didn't use NVRAM.  Thanks.

Well Kamikaze may not use it very much, but the bootloader does.  It is CFE that checks boot_wait.  This is easier to see with serial console.  Also from console you can just interrupt boot, and put it into wait mode for TFTP with a few commands.