make sure you watch the part where the guy uses a hair dryer to melt the sealed edges.. I missed that part and tried to pry my Ipod appart, and shattered the whole thing.
For the iphones you can get units that have all the good on them .. digitizer etc... More expensive.. but a whole lot easier than doing all that hairdryer bizness.
You can save alot fixing these things yourself bit it is/can be time consuming... so if you dont have the time I would have someone else do it... Personally I wouldn't mail it anywhere I'm sure theirs some rinky dinky electronic shop that would repair it same day for you local.. check craiglist.
Ive repaired DS's, iphones, ipods all sorts of portable electronics using kits and stuff.