Yes you can, what you would do is download and install the apps to iTunes (VIA Dragging it into iTunes).
Then navigate (Windows) to "C: \Users\(Your Username)\My Music\iTunes\iTunes Media\Mobile Applications"
Once you've found that folder, plug a USB in to your computer, and Copy and Paste those apps that you want on a different computer onto the USB. Then go to the other computer, navigate to the folder listed above, and C & P it there, and all done (don't forget to Drag and drop those applications into the other iTunes)