Hey i know this is a very basic question but does anyone know how grab a still off FCP 3 and save it as a JPEG? Cheers.

It's a little different in FCP 3 and FCP HD. But as I recall, choose File > Export > Quicktime. Then choose Still Image. Use the options button to choose file format. If you want a JPEG, click the options button there too and select highest quality. Otherwise it defauts to something pretty ragged.

Now once you have the still it will be 720x480 (NTSC) which is not going to be the correct proportion on a square pixel device like a computer monitor. So using Photoshop you will want to resize to 640x480, or perhaps 720x540... or anything with a 1.33 aspect ratio.