If you tried to install VS 2008 , you will notice the the download button will install a small exe file which will connect to Microsoft servers to install the sp1 using online mode.
What i didn’t noticed is that there is a small note in the download page which is under the instructions sections(one of my friends told me about it) , the note is :
“Note: this service pack is also available in .iso format.”
Which means that you can download the service pack as offline copy from the SP1 installer so that you don’t have to install the SP from the internet every time you need it.Also i find that the offline installer is more practical because my internet connection is not stable.
Hope it help someone.