If you can put up a WSUS server you can have it download the updates once and distribute them to other machines. You can modify the local group policy of each machine, if you don't use Active Directory (and thus can't use a Group Policy Object), to direct them to your WSUS server.
Failing WSUS, you might consider downloading all the pending updates and use a tool like nLite to slipstream the updates onto your installation media.
This is a real hack, but one other thing you could do would be as follows:
Install one of the machines and allow it to download updates from the "Windows Update" site and present you with a "Ready to install updates" dialog. Then, perform the following:
for "usebackq delims=" %i in (`dir /s /a /b update.exe`) do start %i /nobackup /passive /norestart
for "usebackq delims=" %i in (`dir /s /a /b update.exe`) do start %i /n /passive /norestart
(Those commands will install most of the pending updates silently w/o making backup copies of the replaced files. Be aware that .NET Framework update, MSXML updates, and application updates won't be installed by this method.)
Install the other 2 machines but don't allow them to perform updates automatically. Copy the contents of the "%SystemRoot%\SoftwareDistibution\Download" directory from the first machine to each of the remaining machines and perform the procedure above on those machines.
Remove the contents of the "%SystemRoot%\SoftwareDistibution" on both machines while the "Automated Updates" service is stopped, then reboot and allow the machines to detect updates again. The remaining ".NET Framework" and other updates will be detected and installed.
(That procedure is basically what I do when prepping a new machine w/ updates from WSUS. I manually execute the updates that don't install via the "for ..." loops when they're done, then clean the machine up. I detest having the "$NtUninstall..." directories on brand new machines, and that method prevents them from being created...)