Probably many such devices. I've put large plants on a simple pulley system, as well.

Here is a link that might be useful: Looky here.....

Lee Valley has a plant pulley called E-Z Up (#AE401)

They also have PlantMinder Water Bulbs
http://www.leevalley.com/garden/page.aspx?c=1&p=53941&cat=52&ap=1

A little spendy, but if it saves jumping on a ladder every week, might be worth it.

Here is a link that might be useful: E-Z Up

Go to your local building supply store and by a rigid 8' length of steel or copper pipe. Either threaded or plain depending if you can solder. Attach a curved water wand to the end of it. Fiddle with a couple of fittings and for a couple dollars and a quarter the price of a 'fancy store bought model' you can reach quite high. (try the fittings in the garden and plumbing sections).

Don't order the ones called easy reach. The pots just pull the pulley line all the way down and it will not go back up and lock. This is a scam.