Yes, you can download tons of themes. The easy, safe way to do it is go to Sony's website. Use your computer first to see the themes and choose a few. After you find the themes you like, use the WAP browser on your phone and download them directly from Sony. They have some decent ones. If you want to try elsewhere on web, there are several other sites with different themes that can be more to your liking. They may or may not work as well.
Hi, I have got one solution for having themes in your Sony Ericsson W810. Check out this site ddnmobile.com. It has numerous free wallpapers and themes, select your favorite themes or wallpapers and move it to your mobile. Positive thing about this site that (ddnmobile.com) is that you can easily download free themes and wallpapers and it really reduces time for creating themes. I hope you will like it.