Since I got my Nokia E61 last month, I've been resisting the urge to put a screen protector on its screen. My logic is that since it does not has a touch screen, like the Treo 650, it is built much less flexible so subsequently requires less protection.
Well, that part is true but unfortunately things (read face and hand) still come into contact with the screen and leave oil and dirty on it. Keeping it clean almost becomes a ritual before and after every usage. So finally I gave up and ordered some screen protector last week. Originally I wanted to get some from BoxWave whose screen protector I used on my Treo and was impressed by it. Their screen protector is not the normal thin, very flexible, and very sticky type. Rather it is constructed with thicker than normal clear plastic, making it much stiffer and easier to apply to screen without any bubbles. Also it uses a mild adhesive that attracts almost no dust during the application process. Unfortunately BoxWave doesn't have one that fit the E61 yet but after some searching on forums I came across another company that makes similar screen protector called Martin Fields.
When I opened the package, I was relived that Martin Fields' screen protector is very similar to BoxWave's. After cleaning the E61 screen with screen cleaner, I applied the screen protector with ease and got no bubble or dust. The size is almost perfectly fitted to the actual screen so there is very little gap remains unprotected. Clarity-wise it is very good and unless one looks very closely it is almost undetectable.
So now I can use my phone without worrying about making the screen dirty.