real error handling
XHTML support
split listings across multiple pages
allow individual time zone for users
online/offline status indicators beneath usernames
topic subscription
email and Jabber topic notification
RSS feeds for latest posts/topics
word censoring
gzip output compression
show/hide email option for each user
database backup facility
version checker
user signatures
hyperlinks for last post in topics
flood protection
ban area in admin panel: usernames, email addresses, IP ranges, hostnames
topic listings filter controls (sort by etc)