whats causing this

hey all,
a kind soul has pointed out that I have "slop" in my stearing. see movies

so I'm gona take it to a shop, (gonna have my u-joints and transmission/engine mounts replaced too) but I wana know what needs to be replaced so I can talk to the mechanic.

please see the vids and tell me what needs replaced to fix this "slop"

http://www.math.ucdavis.edu/~caverick/pictures/MVI_2218.mov
http://www.math.ucdavis.edu/~caverick/pictures/MVI_2219.mov

thanks :cheers: