D3lphin in Kubuntu 7.10 doesn’t have KRename in its Actions menu - a grave flaw. You can fix it by putting the following in a file called, say, krename.desktop in the ~/.kde/share/apps/d3lphin/servicemenus/ folder:

[Desktop Action rename]
Exec=krename %U
Name=Rename with KRename
Icon=krename

[Desktop Entry]
Actions=rename
ServiceTypes=all/allfiles