I can think of countless uses for anything with Teleport. Cosmog and Natu are really puny things that can learn Teleport so I could shove them into like a fanny pack or something and it'd look like I'd be the one teleporting. I could get away with ANYTHING and go ANYWHERE. If there are limitations to Teleport, let's remember that an Abra can teleport you from the Pokemon League to New Bark Town, which is probably a fairly decent distance in real life. If you did that in small spurts you could get good distance out of it. If it takes up a lot of the Pokemon's energy, well- I mean, Teleport's got up to 32 PP.
Now let's say ISIS gets a Groudon. If they have a Groudon they can terrorize the whole world. But if they can find a Groudon, the US or some other superpower would be bound to find Kyogre. So we'd have a crazy, likely apocalyptic battle. We might get Rayquaza's attention with those two fighting. If the side with Groudon was there first and then Kyogre was summoned, Kyogre would win since its Drizzle would overwrite Drought, and vice versa. Rayquaza comes and whichever side captures Rayquaza is the winner.
I was also thinking that if you had a Goomy you could throw it at people. It would work well since Goomy is soft and likely wouldn't take much damage from high impact tosses.