Can I use PNG files in Photoshop?

[tilt]

png works fine in photoshop and you can also save as png

[Korrigan]

I know this thread is a few days old but in case someone had the same problem there is one solution that hasn't been covered. You can use File > Import instead of File > Open. This will immediately add your PNG as a new layer. It is imported as a smart vector object (I guess it's how it's called in english) so that it retains its original size informations and you can resize it multiple times without losing quality (with a normal object, once you scale it down you can't scale it up again without losing quality). If you want to apply filters to it, you'll have to right click the layer in the layer stack and choose rasterize layer, though.