While this idea isn't for everyone (if your partner is shy, you might just want to skip it!) but for those who want to go all out and truly profess their love in front of the world, there are many options available to you.
Consider calling the local radio station and planning out a public dedication to your partner. Just make sure to time it correctly so that they are sure to hear it! (Tip: Consider taping it to offer as a keepsake).
Create a sign or banner that goes into your front yard or a magnetic strip that attaches to your car professing your words of love. This a fun and playful way to show your partner that you want the whole world to know how much you love them!
Consider hiring a local plane to carry a banner over your home that carries your message of love. While this can be quite expensive, it's a rather classic idea that's been used for both proposals and special Valentine's Day romance.
Place a classified in your local newspaper that describes the love you feel for your partner. Make sure to keep a clipping, this one is certain to go into the photo books!