If you have handwriting as terrible as I do, you can't handwrite anything, especially when you are sending or showing it to another person. That is why I love these calligraphy stamps.
Calligraphy Love Stamps
From Paperfinger via The Haystack Needle
Calligraphy Address Stamp from Barbara Kua
The address stamps are a also a great affordable alternative to having your calligrapher add your return address to your invitation envelopes...just buy an address stamp in the matching style and stamp your envelopes (carefully!) yourself. And then you can use it on all of those thank you cards you'll be sending too.