I found this on the front page of the Utah Bicycle Coalition website:
Share The Road License Plate
Coming Soon to a DMV office near you!Plates will be available after October1st, 2009
You will be able to order plates to replace your existing at anytime after they are available. The fee is $25 in addition to the regular registration & fees.
If you order mid-year replacement tags, your registration date will not change and the fee is not pro-rated. (You'll send in your $25 and a small mailing fee.) Remember the $25 goes to a good cause!
For general information from the State, Click Here. Not all locations may have plates, but they will be made available through mail-order from the State.
For questions for the UBC regarding the STR plates, Click Here
Above is a mockup of the current plate design.
Utah Department of Transportation will collect the $25 fee, most of which will be placed in a "restricted account" for use by the UBC for "support bicycle operation and safety awareness programs." For the full text of the law Click Here (look for underlined sections).
Below are states which currently have plates, as of January 2009
Green are states that have a Share the road plate available, dark grey are states that have limited availability of STR plates, and light grey are States that have not yet adopted a STR plate.