Hey.
I'm using SnagIt! to take screenshots - but if I want to take stills from a trailer for example for use in a cstm cover - is there a better program - or a way to keep hires?

If you are useing Photoshop CS3 Extended and have Quicktime pro then you can use HD Trailers in photoshop and save single frames. Try this TUTORIAL http://www.dvdcoversfuzion.com/forum/showthread.php?p=10463#post10463

Snag it I am going to assume takes a pic of your monitor. So if you have the player window open to 50% you will get the current frame being played as well as the desktop of your computer. If that is the case, then yes there is a better way.

Most media players have a "capture frame" option. You will have to go into your options to set up what format it saves as and if it is the actual frame or a chopped version. This information can be found under you players help files.

Now as for trailers. If it is a trailer of the web than it is more than likely compressed to make it manageable to transfer. There is not much more res you can get from those. If it is a trailer off a disc then you are in luck as the capture frame when set correctly will give you a nice image.