I am getting ready to paint my entry hall and stairway. The stairway has a very high ceiling. I don't want to put a ladder on my carpeted stairs to reach the high parts. What tool(s) should I use? And since I'm not painting the ceiling, how do I get clean lines since I won't be able to reach to tape?

In my opinion, the only way to paint properly whenever you must meet a different painted surface is to get right up to it. I've built fairly elaborate scaffolds for this purpose. There are a variety of edging tools that could be added to a telescoping handle. The results might be lower quality than you want but the height of the ceiling might allow you to accept "good enough" results.

Put down a dropcloth or lay carpet shield on stairway. Then set a ladder there.
There's no way around it. If it's over your head you need a ladder, or some sort of staging.
How else can you cut the corners and top of wall?

Matt
Cupan Custom Tile and Paint
Charlotte Paint

Yep you need to get a ladder. You should be putting a drop cloth on your stairs no matter what because rollers splatter. You have to get up there. The "Little Giant" ladder systems have ladders that work on stairs. (One side can be higher than another) This is how we get to the top of high stairways. You may need to use two ladders and a plank. If you tape the top of the wall be careful not to rip the paint off the ceiling and be sure to remove the tape immediately. We don't use tape and instead cut in with the bristles of a good quality brush like Purdy or Wooster. If you want it too look very clean and just can't get up to it you might have to call a painter in. But watch how they do it and then you can just follow their lead in the future. Good Luck!

Lee