Success! :fruit:
It works for me. I got SP3 slipstream into XP SP2 cd. I use Winsupersite.com methods.
FOLLOW INSTRUCTION CAREFULLY!!!
Download SP3 stand alone file from M$ and create two new folders in C:\ drive, xp and sp3. Then move SP3 stand alone file to sp3 folder. And Copy and paste all XP file from CDrom (unhide all file so you can include hidden files). Then do the command prompt:
cd \ [ENTER]
cd sp3 [ENTER]
windowsxp-kb936929-sp3-x86-enu.exe -x:c:\sp3 [ENTER]
It will unpack SP3 file and automatically create new i386 folder on C:\ drive
Next command:
cd i386 [ENTER]
cd update [ENTER]
update.exe /integrate:c:\xp [ENTER]
I got it working and slipstreamed SP3 into XP folder.
Be sure you use ISO Buster and extract microsoft.img into sp3 folder then run Nero's Burningrom (not Nero's Express) and follow instruction carefully and to open the .img file to save, on the bottom of file name, ".img" would not show up on sp3 folder so click and see drop down and choose all file " *.* " Bingo! you should see Microsoft.img and save it.
Last thing is Be sure the CD name before burning it to CD should be exactly the same as original CD so it'll boot up and installs XP without naming issue.
I've test ran XP SP3 cd on VMware and it work perfect!
Catty 
