Exactly what he said, go transparent and that could look tight. If you don't know how... Magic wand all the white, then Select Inverse so your logo is selected. Click CTRL+C. Now, click File > New and the sizes will be enough to fit it (Photoshop automatically sizes to fit your current thingy copied on clipboard). At the bottom change the Background from White to Transparent, and then click Ok. When the new window pops up, click CTRL+V and it'll paste on, then save it as a .png and wala, transparent edges. Um, you probably already knew it, but i'm in an odd mood this morning >.<