For Daniel Monsanto, author of Postcard History Series: Houston, it began with curiosity. What did Houston look like before there were skyscrapers and modern buildings here? He found his answer in vintage postcards and has spent the last 17 years building an impressive collection, including a number of images of Houston at the turn of the 20th century.

Monsanto, organizer of this weekend's Houston Book, Postcard & Paper Festival, says collecting postcards is seeing a resurgence of interest. "It's a lost art that might be getting found again," he tells Art Attack. Surprisingly, it's digital technology that's helping to boost the newfound interest as making individual postcards is easier than ever with personal computers and easy-to-use software. "You do have some people who are making their own postcards and sending them out, and creative types who are putting images on them and printing them on demand. I think it's leading to a little bit of increase in mailing postcards. And the Internet has helped dealers who can now sell thousands of cards through an online store.

"But I don't know where it's going to go from here, or what the long-term impact of technology will be. Our communication has become electronic and it gets deleted now. All these wonderful text messages and photos we send back and forth are replacing postcards."

While his collection has grown to include dozens of other subjects, most of Monsanto's favorite cards have a strong Houston connection. "I have a photo of Ellington Field with biplanes flying in formation over it. It's from the WWI era and I've always thought that was one of the neatest cards I've ever seen.

"I have a card from around 1898 of Houston, showing the tallest thing to be the courthouse and a couple of church spires. And I have one that's an aerial view of the city from what they called an 'aeroplane.' That's pre-1920."