I agree with Boogie. Autopunch is the way to go. Although there are those in this forum who don't agree for some crazy reason.

Much safer for super tight punching than stepping on a pedal and hoping you got out of record on time. (Although one of my clients nicknamed me "Toe Master" because of my punch in technique with my ADATs.

My Peavey midi controller pedal can also turn on/off effects on the processor.

I just want to say how frustrating it is to be here, years later (I'm using 8.5) and (as far as I can determine) still not have the ability to map a pedal action through key bindings.
 
To all the folks who just can't imagine why it would occasionally be helpful to be able to punch (or whatever) by foot pedal instead of using a finger on a keyboard, all I've got to say is, Why do you even care? Just because you can't imagine why someone would need a capability doesn't mean they don't. 
 
For the record, I've been using CW/Sonar since my first 8 channel DAW with CWPA 6.0 in late 1996.

I have used an X keys USB footswitch since this thread was first posted. I'm suprised nobody ever bothered to Google USB foot controllers and get the easy answer. 
 
http://xkeys.com/XkeysFootPedals/index.php
 
I use mine to stop/start and advance my live performance playlist in Win Amp. You can record and save any Macro ( keystroke or mouse click ) including Spacebar, "R" and "W" which I use for Sonar no problem. It's nice to keep your hands on your guitar while performing. 
 
Mine is getting worn out but they still make it. It is very heavy duty but I paid $150 for it. I see I can get a 3 way switch for a low as $40 but not sure if it would hold up as well. I think I'll order this and see. The X Keys software has not been updated so I'm interested to see how this one is before I spend $150 again. 
 
http://www.amazon.ca/FS3-M-Triple-Switch-Control-Keyboard/dp/B00FWD2S78
 
PI who makes the X keys has this now which seems even more interesting as it can run up to 12 switches
Brochure: 
http://xkeys.com/assets/sell%20sheets/Switch%20Interface%20Info%20Sheet.pdf
Web SIte: 
http://xkeys.com/xkeys/xkswi.php
 
 

Auto punch is the way for me.  I really can not envision why there would be a need to use a pedal/footswitch to punch in and out with the power and functions of the modern DAW.
 
I used to have to do that on an old tape based system and it was such a pain ....and not accurate by any means.
 
With setting the auto punch in/out points, and by zooming in as needed, you can make that punch exactly where it needs to be, locating it between 2 really close notes for example.... it is flawless and surgically accurate.
 
The auto punch will always come in at the zero crossing.... the pedal might not.
 
just my 2 cents

I don't use my footpedal for punch in, just start/stop. And I agree, I would never work that way anymore. It was common with our old hardware machines to use the footpedal and it was never perfect. It did it then and will do it now = create pops and clicks because it has no way to hit a zero crossing.  
I have my own method that works great for me.
 
For fixing mistakes in a track: 
Clone the track
Delete the audio in the new track
Split out the bad part in the original and delete, this creates a space. 
Arm the new track and start a few measures back from the mistake ( blank space) 
Record new part
Now trim with slip edit and drop new take into space in original. 
I find this faster than setting punch in points. 
It also allows you to fiddle with the crossover point with the slip edit function. Punch in often results in a click or pop.