Wireless Security Camera's for home use.

Wireless cameras with net access are pricey because they are hard to develop and build.  It would likely take more in raw parts and asociated dev tools to build up a workable solution for single unit project.  It's definitely not out of the question, but the magnitude of a project such as this would be diving into the deep end in terms of both time and money.  Amazon has several sub $100 finished products that would do what you want.

I think this is prob what you're lookin for:

http://www.vuezone.com/uses/takeapeek/index.html?utm_source=Bing&utm_medium=vue&utm_term=avaak-vue&utm_campaign=Branded-EV

Cameras are bat powered, and It works from your computer or smart phone.

Try CamWiz software plus a Logitech webcam.  You can use an powered USB extender to get the cam out to 10M or more. 

CamWiz can send SMS or EMS (through your provider's SMS or EMS gateway), or you can have an email sent, for "instant" phone notification of movement.  Of course you need an iNet connection for this.

If you want to be sophisticared, use a Foscam PTZ cam and control it remotely (there are Foscam knockoffs cheaper than the real thing if you don't need any support... but no support isn't for the faint of heart the first time around).  Foscam is cheaper than an commercial PTZ cam by nearly an order of magnitude, but you lose a lot of reliability vs. a commercial solution.  A broadband connection is the only practical way to implement this.  (control can be via a DN you rent, via smartphone or other browser)

These are the solutions I am currently using. 

Note:  you may want to have unlimited SMS or EMS until you get the bugs worked out.  Receiving hundreds of EMS messages due to the grass waving in the wind can be expensive if you have to pay for each message.