My roof is taller than I'm comfortable getting on a ladder. I've got a couple weeds/trees starting to grow in them. Is there a tool that would somehow let me scrape or use water-pressure to clean the gutters?
You may want to look at something like the Gutter Cleaning Wand:
You don't need to hire a professional to clean out your clogged rain gutters. Attach the Gutter Cleaner Wand to any standard garden hose, and you'll be able to clear out those debris-filled rain gutters yourself. This heavy-duty hose attachment has a telescoping wand that extends from 41.5 inches to 68.5 inches to get to those hard-to-reach spots along your roof.
- Rain gutter cleaner attaches to any standard garden hose
- Spray nozzle directs water flow to blast away debris
- Gutter cleaning device extends to 68.5 inches to aid in reaching remote areas
The iRobot Looj may help you - it is a gutter-cleaning robot. I've never tried one, but I do have a Roomba (which I can attest works quite well) and these are the guys that make military/bomb squad robots.
You still have to get on a ladder to get it in, of course, but you don't actually have to climb onto the roof.