I'd recommend asking around to see if you have a friend with a DSLR camera that shoots video. With a little bit of practice you can easily get the shots you need to put together a nice video. I think people think it's scarier than it is, and I assure you I am an amateur, at best.
Key idea is to keep the video simple and fluffy as when you start to get specific and detailed it all becomes complicated. Getting the message across should be done in around 30 seconds to capture and fire up a potential audience.
If you have a Mac with iMovie you can easily dump those video files and start messing with it.
Ping me if you'd like any specific information or to bounce off ideas (my favorite thing to do).
Although Blurts is a completely different approach than the other two examples you posted. Same rules apply, just add a camera.
http://adamlisagor.com has been doing some really interesting promotional videos for apps and web services.
But this all really does boil down to how much you want to spend, as far as talent goes. You can find a savvy college kid or hire someone who does this sort of work full-time. Or make something a little less sub-par and do it in house.
All in all the shooting took about 20 minutes and the editing an hour or so. Fun little project with a couple friends :)