Don't get lost in the post-wedding shuffle. Take these steps to make sure you keep your records up to date.

Driver's license or DMV ID card
Bring your current license plus your marriage license or certificate to the DMV. Be sure to change your name and address. It makes your life easier to change this first, and quickly!

Bank accounts
Bring your new driver's license or receipt with you. Also bring your marraige license or certificate. Be sure the bank changes your name on all of their records.

Social Security Administration
Bring your marriage license or certificate. Many processes are tied into this system, including Internal Revenue Service records and most federal systems. The record must be formally changed or you could get a letter from the IRS saying you did not file a tax return, just because they were not told that you are no longer Jennifer Jones, but now Jennifer Jones-Smythe. Warning: This is not a way to become invisible to the IRS. They will find you.

Medical records
This one applies to both husband and wife. Notify doctors, hospitals, insurance carriers, et. al., of the change in your marital status. Also, update your next-of-kin contacts for emergencies and consider making organ donor, life insurance and critical care decisions together.

Mail delivery (USPS)
Just mention to your letter carrier that you have married, so the person will know that your magazine subscriptions coming in your maiden name should still be delivered to you at the same address. If you move, be sure to put your old name and new name in the right place on the forwarding order.

Credit Cards, utility bills, finance companies...
These folks need to know, too, so you won't lose credit under your unmarried name and you will be able to obtain credit under your new name. Most companies have toll-free service numbers for reporting such changes.

Finally
A few weeks after you get married (or right away in some cases), go to the Recorder's office and get a certified copy of your marriage certificate. It's handy to have if you move (and it looks nice framed and hung on the wall).

You might want to consider printing address and name-change cards that you can mail to friends, relatives, and businesses.