i recently bought an smt5800 and for these past couple days all i've been doing is researching how we can mod our phones...So far this is what i found..

Because we have a sliding out fone, we cannot just get any homescreen, we need to get hoemscreens that are either customized to our fone the smt 5800 (s720) or homescreens that are customized to the s710 and s730 phones (they have sliding out qwerty keyboard as well). There's different plugins which our fones can use, but those plugins need to be linked in the .xml files (these are the files that display the homescreen). First you need to unlock your fone in order to install anythign inside the fone (see above). A classic homescreen for our fones is the HTC homescreen, but i don't really care for it since it only displays one line of the calendar, instead of whats going on today AND tomorrow or the next day. The best homescreen can be found here:

Skins for Vox (plugins : HTC Home/SmartMonitor/CBReminder) - xda-developers

Hope this was helpful.