It's a bit late to be blogging right now but I felt like I needed to do some research. I do like my last name, and I am intrigued to know of its origin and significance. It is a compound-word surname and a variation of "Blackburn," which comes from the location of the same name in Lancashire, England. Just for kicks, let's examine it more in depth. Here are a few definitions:
Blag - A phonetic derivative of the word "black," as in the color of coal, ravens, night, or outer space. To blag may also mean to gain access into a private club or party. Lord knows I've tried that!
Burn - "Burn" refers to an Old English word for a brook or stream. To burn may also mean to combust or to light on fire. I tend to not light things on fire though. :-)
Ideally, a "blagburn" is a peaceful river reflecting dim light on a typical British afternoon.
It is also interesting to note that, according to the Online Etymology Dictionary, the same root relative for black produced the word bleach as well... This may be "perhaps because both black and white are colorless, or because both are associated with burning" (source).
The Blagburn surname is recorded to have been around since as early as the 16th century, and I hope it continues to do so.