We've decided to use Vistaprint for our STDs, invitations, and other paper products. Vistaprint almost always has some sort of discount going on (especially if you sign up for their emails). They also frequently offer Groupons (to the likes of $15 for $60), so it's a great way to get beautiful invitations for cheap!
Save the Dates
This is the design we used for our Save the Dates. We thought they went very well with our Aquarium wedding! Our Save the Dates are actually Vistaprint's Large Magnets.
This is our wedding invitations! It's a different feel from the fun, aquarium theme'ed Save the Date. This is an intentional mix up on my part, to ensure that people understand the wedding is a formal evening wedding, but they're still welcome to kick back and have a fun time! The invitations will come with an RSVP card and an accommodation card.
Photo Sharing Cards
Vistaprint offers 250 business cards for free- a no brainer! We used them as photosharing cards. They include information on a photo uploading site, username and password, so that all our guests can upload their pictures in one place after the wedding!
I had an expiring Vistaprint groupon I needed to fill, so when I ordered my STDs I also ordered this lawn sign to place outside the Aquarium. Free products are great!
We stuck with a purple-ish theme, and used these flat invitations for the rehearsal dinner invites. They were nice because we could put directions to the restaurant on the back of the invite.