Log Bird Feeder - 23 DIY Birdfeeders That Will Fill Your Garden With Birds (my note: I haven't looked at all of these, but at least one is a terrible idea. The window birdfeeder -- birds could fly into the glass and hurt themselves.
Outdoor shower/water day for kids.Could easily be made with hollow box uprights, run the water tube through one and the top hollow box with a PVC tube that you drill holes in for the water to run out. Faux paint it to look like copper, really pretty easy.
AWESOME - Maybe with a Solar Light. Might even carve house number into the post and put lights behind it for a light up effect. How to make this garden lamp out of pallet wood and a mason jar. Bollard style lamp posts are easy to make and costs pennies!