A hover menu is a small menu that appears when you hover over userheads/icons. It shows the user's default icon, a link to their profile/journal, the option to add someone as a friend, and whatever else the site offers as features (LJ for example has a link to Private Message a user, add notes about the user, etc).
The site schemes offered are kind of bland and unattractive; The site font needs to be changed to Verdana all across the site, because its current font is... sort of unappealing. The color schemes and stuff also need... well, tweaking (lol).
The stuff you do offer is cool, like the Browse button and icons, though.