go launcher, launcher pro, and adw all support customizable dock bars (there are other launchers out there that i haven't tried)
go and pro have dockbars that by deault have 5 items (launcher pro (maybe also go launcher i didn't mess with it as much) can be made to mimic froyo dockbar with homescreen dots) with up to 3 dock bars which you scroll through by swiping across the dockbar
adw supports up to 5 items on the dockbar with an optional hidden dock (not sure what if any limits there are to how many items can be placed in adw's dock)
these launchers also give extra options for other things like extra home screens (i believe most if not all max out at 7) fewer home screens (maybe you only use 3) app drawer improvements, etc