Ooh, then can I summon dragons to use as a mount? I saw that in a movie once and it looks really cool!
Seriously, though, "Because it would be cool" is a crap excuse. You might as well allow people to turn off gravity, or do other idiotic things. It would be really cool to have a lightsaber and use it to block bullets, but that's not possible in Shadowrun. Star Wars Saga edition? Yeah. Mutants and Masterminds? Sure. Hero System? Of course. Shadowrun? No. Both from the mechanics and the world standpoint, it just cannot happen.
The whole 'summoning programs into the real world' thing sounds cool as part of a superhero game (in fact, I've played a character with similar abilities in a superhero game before), but as part of Shadowrun, it is just a truly godawful idea.