Skateboarding for 3 year olds these days requires some investment such as skateboard, helmet, knee and elbow pads, and driving to a skateboarding "ring". But with some imagination you can do it on the tight budget as well:
- skateboard from Goodwill -$3
- bicycling helmet - already had it.
- Knee, elbow pads and protecting gloves - make it yourself. Instructions: wrap kid's elbows and knees with adult size socks, then take old adult socks and put it over the arms and legs (see picture). Fingers go through the special holes.
- skating ring - find a loading dock at the nearest business store or warehouse (those are usually closed on weekends) and skate at the ramps and loading docks.

Lots of complimentary excitement from the kid!