4 + disallow login if user is logged in
5 + disallow register if user is logged in
6 + common_current_user()
8 + session variable for login
13 + subscribe links on profile
16 + disallow direct to PHP files
17 - require valid nicknames
19 - configuration system ($config)
20 - RSS 1.0 feeds of a user's notices
21 - RSS 1.0 dump of a user's notices
22 - RSS 1.0 feed of all public notices
23 - RDF dump of entire site
26 - make sure canonical usernames are unique
29 - design from Open Source Web Designs
33 - add subscriber remote
35 - receive remote notice
37 - tinyurl-ification of URLs
38 - jQuery for as much as possible
44 - stay logged in between sessions
45 - use RSS as a subscription
51 - forward notices to Jabber
52 - forward notices to other IM
53 - forward notices to mobile phone
56 - include twitter subscriptions
57 - include Pownce subscriptions
59 - Wrap DB_DataObject with memcached caching layer
60 - login throttle to prevent brute-force attacks
61 - form token in login to prevent XSS
63 - Atom Publishing Protocol