Just today techrepublic published this artickle:
https://www.techrepublic.com/article.jhtml?id=r00220010918low01.htm
We use Famatech radmin to remote administrate users and servers over lease lines which works greate.
So at least you don't have to walk (or drive in our case) to the users anymore.
for the dialup users I dont have a really good answers since even if you download the update and share it on the network their connection may be too slow to install it remotely.
You can subscribe to the Technet of MS and buy a cd with the updates of MS.
For the Online users you can use www.windowsupdate.com , but you have to do that on every pc.
A better option is go to http://www.microsoft.com/downloads/search.asp? and download theupdate you need only once, copy that to a shared folder and use a remote admin tool so you can update the pc remotely.
MS has create once a software to do exactly did once , I forgot the name (SBS or SMS i think).
You could created distibuted packages on the server and when the clients logged onto the network it would automatically install the updates.
Will try to track the name of the package.
regards,
Leopold