We recently made Psi's dialogs related to account creation, registration, and modification a bit easier to use. The account registration process is now a wizard-like dialog, where a user first needs to select a server (from a centralized on-line list), and then needs to provide the information requested by the server (according to XEP-0077: In-Band Registration). We have also introduced new default settings that should avoid the need to tweak any account settings when adding an existing account. This means that you should be able to log into any XMPP server (including Google Talk) just by entering your JID and password. Some more details and screenshots below.
Removing the need to tweak account settings was done by a combination of new 'Encrypt connection' and 'Allow plaintext authentication' options. For 'Encrypt connection', there is a choice of 'Always', 'Never’ (mostly used for debugging), 'Automatically' (which uses encryption if TLS support is available), or 'Legacy SSL', where the default option is to encrypt traffic when it is available. For 'Allow plaintext authentication', the options consist of 'Always', ‘Never', and 'Over an encrypted connection', the latter being the default. A combination of these 2 defaults makes that you should always be able to connect to a server that is compliant to the XMPP1.0 specification, without allowing anything less secure than what the spec allows.
One more thing on our TODO list is to allow importing (self-signed) server certificates. At the moment, most users still change the option to ignore all SSL warnings, which is less than desirable from both the security and the usability point of view.
Below are some screenshots of the reworked account dialogs.