After considering a few different options, I decided the best way to do a guestbook was to use an external service which provides guestbooks for other sites. I went with 123Guestbook.com as my provider of choice. Note that I am not sponsored or affiliated with 123Guestbooks.com in any way, and I am not paying for any services they provide.
Before posting to my guestbook, you may want to consider reading the provider's Privacy Policy and Terms of Service.
Please be respectful and kind to other users, even if you disagree with them.
Do not post any personally identifiable information. Please note that other users cannot see your IP address, but they can see whatever you put in the email address input. It is not reccomended that you submit your real email address, but feel free to put your social media handle there instead. Also, please note that I (the site's creator) can see your public IP address. This is a requirement by the guestbook provider which I cannot turn off.
Do not post links to any content that is illegal or disturbing. Also, please refrain from posting pornographic content. There's a time and place for everything, but not now.
If you have any questions, you may reach out to me.
With all of that being said, feel free to sign my guestbook here!