Have you heard the news?  The USPS will again raise the price of stamps.  Right now, the prices are:

Envelopes that are 1oz or less are $0.41.
Envelopes that are more than 1oz and less than 2oz are $0.58.
Envelopes that are more than 2oz and less than 3oz are $0.75.
Square and vertical envelopes require an additional $.17.

As of May 12, first class stamps will go from $.41 to $.42 each and the heavier mailings will go up as well.  But, the post office now offers Forever stamps, where you can buy them at the current 41 cent price and you can use them forever, even as rates go up.  The only problem with that?  There's only one style, the liberty bell.

American? Yes.  Does it define weddings? No.  I actually do look at the stamps that come with wedding invitations as I think they add to the overall design and attitude of the invitation and event.  However, these forever stamps would save you money and would be great for return envelopes, invites to other related parties such as rehearsel dinners, brunches, your thank you notes even.

You could always get some more colorful and event specific stamps and then add on the 1 cent stamps to add some more pizzazz.  There is always the traditional wedding heart stamp

or a great stamp for spring and summer would be these beautiful blooms: 

Then, there's the more personal approach of getting your pictures on the stamps, a fun recent trend.  Photostamps.com offers personalized stamps with your picture on it for only $5-$10 more than postage.  You can use an engagement or casual fun shot for save the dates or invitations and a wedding pic for thank you notes!