shot with a circular polarizer

Yeah, I must be getting ripped off... bought one of those Super Thin $140 ones... and those L lenses, why did I ever spend all those thousands of dollars on L lenses, when a $200-300 lens is the same.

Naw, there has to be a difference, because the other option is they (the companies) have brain washed all of us ... I think

Better filters deliver better sharpness. I was using a Cokin CPL on an old lens and it was the best CPL I've been using. I'm still using it sometimes by just holding it in front of my lenses. The effect is not as strong as with my new SUNPAK CPL, but the sharpness of the photo is the same as without the filter.
I was using a double-glass TIFFEN CPL for a short time. It was outstading - I was able to turn the sky to almost black color. But the double glass destroys the sharpness of the photo much more than the single-glass Cokin.
Now I'm using a single-glass cheap SUNPAK CPL and it's OK. Not as good as the TIFFEN, not as sharp as the Cokin, but just OK.

I agree for the L lenses. A couple of days ago I took a friend's 16-35/2.8L to make some tests. It was exactly the same sharpness as my very cheap 18-55 if I stop down both to f/9. With wider appertures the L is much better, but I don't know who's gonna take landscape photos at f/2.8. Yes, the L is very solid, professional looking lens with smooth action, but I would not spend these ++++$ for it.
It's different with the tele-zoom lenses - I use a cheap 90-300USM, but it's not as good as the 100-400L

Mmmm. Gonna get me a circular polarizer. All my sky shots are gray.

For those of us too cheap to buy a polarizer filter, you can cheat somewhat in Photoshop.

Take an image, select the sky, add a new layer, go to layers menu and
add new fill layer, use SOLID COLOR and group with previous layer (in
PS7, something about masking in CS), change mode to COLOR BURN and
then OK, now choose a light shade of grey and adjust to your liking.

It's not about the sky only. The polarizer eliminates the flare from ALL non-metallic surfaces (water, leafage, stones, clouds etc.). Doing so it increases the saturation, keeping the colors very natural-looking. I don't think there's a way to do the same in PS.
I may post some examples tomorrow (if somebody's interested).

I use Tiffen CP's, there's no way you can easily achieve the same result with photoshop. I've spend hours retouching photos at work to remove reflections and highlights ofcourse it were different pics from those posted here, I know you can add contrast to a sky easily, but with buildings, cars etc, it requires a lot of cloning and painting over to get it right.

Just wanted to point something out here-
By default, lenses and filters will not fit on the Canon A series cameras. However, you can buy an adapter that can go on the body of the camera (the area around the lense can come off) and put an adapter on there. The LA-DC52C is the adapter Canon makes for the A70/A75/A80 that can fit threaded lenses. You should also be able to buy a tube adapter that will allow for using filters like the G series cameras have.