Omni-ware and Dinosaurus can host a program. Hosting is after the ICEbraker is played?

As part of playing it. You chose to play it hosted on the drive or console, as opposed to installing it in your rig.

Same applies to Djinn, which can host any non-icebreakers up to 3 MU (so viruses, magnum opus, sneakdoor beta for example). You choose where to install it as part of the install action, and it can't be hosted after the fact (although you can probably sneak around this with Scavenge).

(although you can probably sneak around this with Scavenge).

Indeed. really sneaky way to get around not drawing your djinn, omni-drive, or dinosaurus until you're almost out of MU.