How can I decorate a gas meter so it isn't such an eyesore?

Build a 3 sided screen that is easy to move. You cannot cover them completely as the gas company may need access to it. You could also put a small table over the top and add a planter with trailing plants like sweet potato vine or vinca and a few flowers.

Linda...Even a flower bed on the side you want to hide. You could put pavers down and add potted plants also

Maybe something like this:

https://www.hometalk.com/diy/grow/landscaping/removable-30370234

You can re-purpose shutter screens https://www.hometalk.com/diy/decorate/rooms/outdoor-repurpose-shutter-screen-7957152

Outdoor Repurposed Shutter Screen

Hi Linda, her's another idea you can try - https://www.youtube.com/watch?v=98W3v6QBoaE