This photo was taken on the street market of Namdaemun (South Korean Gate) back in 2006. It may gross some people out and I am not sure whether you can still find this type of street food in Seoul today.
I remember, there was also a shop selling nice hand made jewellry boxes and here are some samples. They are of the highest quality of jewellry boxes I know of that you can buy off the street side shops. They have really intricate designs and the finishing is just superb.
Sadly, Namdaemun was destroyed by fire back in 2008. The wooden portion atop the gate was severely damaged by in that 2008 fire started by an arsonist.
Namdaemun will rise from the ashes as it is currently undergoing restoration and the work is expected to be finished by end of 2012. So, if you are preparing your trip there in 2013(seems like a long time away) don't forget to visit Namdaemoon and hopefully, these street hawkers and side shops are back that you can see for yourself and hopefully get some souveniers.