Alt+Left / Alt+Right or F5 / F6: switch to previous/next buffer
F1 / F2: scroll bar with list of buffers ("buflist")
F7 / F8: switch to previous/next window (when screen is split)
F9 / F10: scroll title bar
F11 / F12: scroll nicklist
Tab: complete text in input bar, like in your shell
PgUp / PgDn: scroll text in current buffer
Alt+a: jump to buffer with activity (in hotlist)