I made a discovery earlier this weekend. Most states allow you to renew tags and driver licenses online, and pay with a credit or debit card. The state I live in is no exception. In my state, you can either go to the state's website or your local county's website to perform these tasks. The state uses a third party payment company to process these payments, and charges a fee for doing so. Some companies and states more so than others. In the case of my state, the processing company charges a several dollar "convenience fee" when using any payment method at all, probably to cover the expense of the charges the card companies impose on those payments.
However, my county offers the same services, and there is no fee if you submit your payment as an e-check, or ACH payment. I just took advantage of this, and renewed registration on two vehicles for two years each, and saved myself $7 in fees.
A buck here, two there, adds up over the course of a month, or year, and saving that much per transaction results in substantial savings.