I just installed Solaris 10 and I haven't configured my internet connection for it... Well... I'm stuck with 640 x 480 resolution and it makes using it very uncomfortable... There isn't any other option other than that in the settings... I'm using NVidia GeForce MX 4000... Thanks!
What X server are you using? I've used both Xorg and Xfree on Linux and the configuration is the same. I don't know about Xsun, but you can try starting with The Xwindow User HOWTO and the Xsun man pages and see how far you get.