Yeah, all you do is cut some colored cardstock and then punch some circles out of the same color cardstock and stick them on with 3d tape. My son wanted LEGO written on the studs so I did that and it all took maybe at the most 20 mintues. The cards here are 4 1/4" x 5 1/2" and the circles are a 1" punch.
The inside is a whole different story though. I love messing with PSE so I decided to learn how to make a LEGO font for the invitations. The tutorial I used really helped and it's fairly simple. To see it go HERE
The other Lego pieces on the invitation are actually from the Lego program where you can build your own lego pieces. They have every piece- including some minifigure pieces and you can save the pictures as PNGs. I've used these PNGs for the other 2 parties and still have a bunch saved so I just used those images and put them on. I'm sure if you don't want to mess with that you can google lego pieces and find a ton of images.
They turned out great and I got a chance to make some cards- win/win!!