Since Blogger made changes I've been trying to work out how to get rid of those annoying faint grey lines around my pictures! After some guidance tonight on the #bbloggers chat I have now removed them. I had a number of tweets asking for help so thought I would quickly post how I did it to help you!
If you are using the new Blogger Interface (not dynamic views):
Go to your Dashboard - Template - Customize - Advanced - Add CSS - then paste the following code - Press enter after the last character of the last line } - Apply to Blog.
Ta da! The boxes around your photos should have disappeared! If you have any other suggestions as to how I can improve my layout then feel free to comment below.
Hope this is helpful to everyone!