Sparrow tattoos do symbolize freedom, similar to swallow tattoos. You might see several sparrow tattoos in jail or on people just released from jail. Although sparrow tattoos are not just on convicted criminals. There is religious symbolism to sparrow tattoos. In scripture we read that God would not forget even the smallest sparrow so how could he forget you.
The sparrow tattoo became very famous with the popularity of the Johnny Depp's Pirates of the Caribbean series. Johnny's character Jack Sparrow had a sparrow tattoo on his arm. Many people have copied this tattoo. Johnny Depp actually had a real tattoo inked of a sparrow with Jack underneath it for his son, Jack. On his real tattoo, the bird is flipped around and looking inside, toward the body.
To get unique sparrow tattoos you should check out the bird in nature. If you don't know much about birds and don't know if you have any sparrows around, that's okay. Look online for pictures of sparrows. If it's blue, you got the wrong one. Once you see a sparrow and what its habitat is you can think of some things that will make your tattoo unique.
You can always add other animals into sparrow tattoos to change them up a bit. You can also have the sparrow doing something like flying and picking up something or landing on something that is personal to you. Remember your tattoo needs to be personal to you. A good online tattoo gallery will give you lots of information about tattooing and give you plenty of ideas on how your sparrow tattoo can look. A good thing about online galleries is that some charge a membership and then you get unlimited tattoo design downloads. Other sites make you pay as you see a design.