This behavior may be nothing at all to worry about. It may be related to teething or experimentation and may go away. But still I suggest as other respondants have that you get her evaluated as soon as possible. If it is sensory seeking behavior related to a pervasive developmental disorder, the sooner you catch it, the better her prognosis is. Plus, if it is nothing you will have the peace of mind of knowing that. Also, here's a link to a webpage that lists some signs of autism: http://www.autismspeaks.org/whatisit/learnsigns.php#redflags
although this list does not mention sensory seeking behavior (that is behavior like your daughter's), that is usually something you see in children with an autistic spectrum disorder.
Having your pediatrician screen her is a good idea, but I highly recommend having her evaluated by an experienced occupational therapsit trained in pervasive developmental disorders (this is the umbrella term that autism falls under, but there are many degrees of severity starting from very mild.) Many pediatricians are not very knowledgable about this disorder and may tell you to wait and see, but again this lost time is crucial if anything is wrong.
I don't mean to scare you with this information because your daughter's behavior may very likely be nothing to worry about, but early intervention is key with a diagnosis like this, so you don't want to take a chance waiting, just in case.
Again, I'm sure everything will be fine and good luck.