Maybe this will help...
I have looked into both patents and copyrights, as well as having a client who has gone through both routes with his products.
First here is a link which will tell you everything you need to know about the topic straight from the horses mouth:
http://www.uspto.gov/patents/index.jsp
Understand there are (3) types of patents...design, utility and plant. Plant is for creating new strands of plants, so forget about this one. The two you need to concentrate on are design and utility.
Example #1: You create a new design for a crankbait which the lip and body shape cause the bait to turn sideways twice, turn around and clack three times through internal chambers. This example you would definitely want a utility patent.
Your design is unique and causes a new unique function to an existing bait. To thoroughly protect this lure you will probably need some outside help to fully document the makeup of the crankbait and each unique part. This can (probably should) be done with the help of your brother in-law who happens to be a patent attorney. If only we were all that lucky! I say this because utility patents can be complicated and "complicated" can equate to expensive.
The expense can be through lawyer fees, submitting an incomplete patent and it is rejected or getting a patent which doesn't fully protect your design elements and it is stolen. Remember, ANY patent which is submitted and rejected for ANY reason (incomplete, someone already has a similar design...etc.) will result in the loss of all application fees. Basically you have to pay all over again to resubmit.
Example #2: You design a new crankbait which the body shape looks like your hot girl friend from senior high school (the one that dumped you right before prom). It has a curvaceous body, hard wobble and looks Freak N' Awesome! Now other than "looks" this bait runs just like most cranks out there. It dives, wobbles, suspends and slowly rises.
For this you have two choices. The first choice is to get a design patent. You can patent the "hourglass" shape and look. This will cost less than a utility patent (maybe 4k...not sure, check the link), and it is easier to apply for because it is...well...a design, which doesn't have parts or functions which are unique in creating a different action unlike anything else. A design patent is MUCH, stronger than a copyright which can be used for literature, art and design.
Your second choice of course is copy righting the lure. The advantage to a copyright is it is cheaper (about $700 I believe) than the design patent. However on the downside, someone can change the design slightly...-say 15% fatter in the middle and two little dimples on the ends- and now you have an appointment to present your most convincing argument to a jury in hopes they will side with you after your noisy neighbor steals your thunder.
The client I have is a friend and has used copyrights to protect the carvings on his furniture. He knows you can't utility patent a wooden beach chair and it is too pricy for the design patent, so he ops for the copyrights knowing someone could swipe his design and change it slightly.
I know the A-rig has been mentioned above. His patent may have been for design, since umbrella rigs have been around for awhile. He may have sold the patent to Manns, in turn Manns may have sold it to everyone else. I'm totally speculating on this. I am mentioning this as something people do who patent their products.
Also, I want to mention this...you cannot patent something and not DO something with it. This keeps the Warren Buffets of the world from creating patents on items and sitting on them to prevent competition.
Check out the site I posted. It is a great resource!
Hope this helps!