Ok here's the scoop de doop:
1) iRig: is junk, and expensive junk at that. Reason: serious imbalances with the signal. Just what you want for an electric guitar LOL
2) Peavy: is worse junk. Cheap Chinese junk. A TOTAl rip-off that most likely won't even work. Belive it or not, the guitar plug doesn't EVEN FREAKING FIT correctly. You have to jiggle it around as the connection isn't flush or something. On Amazon suckers make comments like: "I had to finesse the cable to get sound but that's ok, it works GREAT if I don't move it. I'm happy!"
3) Apogee: is WAY overpriced, but probably at least works. True value?
$15 US.
Now here's a good one.
4) Sonoma Wire works. These guys are criminals. They are playing to juvenile, budding, guitar dimwits who are by definition brain dead. If you pay hundreds of dollars for this you had better be good at guitar, cuz your unemployable.
Best to just get the connection kit, as going in though the headphone jack is a bad idea. Just Google for Guitar USB cable or whatever. $15/$20 US will get you one that's works perfectly with an iPad. I have a Chinese Ebay version of the Berringer that has everything. (the led is so bright it's like a laser in your eyes though. I had to put tape over it.

)
The Alesis Guitarlink looks like a nice low profile solution. But The adapter I got for about $15, also has a headphone output, a hi-low signal switch, and a volume control and is still low profile. The Alesis is just a simple input cable. Anyway, here's the generic equivalent of the Alesis on Ebay
http://cgi.ebay.com/3M-USB-PC-Guita...ccessories&hash=item415052c491#ht_3297wt_1141
Here's the one I got:
http://shop.ebay.com/i.html?_nkw=us...able+2m&_osacat=0&_trksid=p3286.c0.m270.l1313
note: this is link to a Ebay search for a 1M cable. The link above that is for a 3M cable without the added controls and ports. Something to consider
Just my opinion. Take it or leave it.
