After implemnting FBA in MOSS, in Welcome menu, account name such as "jsmith" rather than "joe smith" is displayed. Very often, people find it very annoying. In WSS, user can simple change the display name by editting "My Settings", but in MOSS, none of "My Settings" fields is editabe.
Why? the reason is, In MOSS, the "My Settings" info comes from user profile. If your FBA data source is LDAP compatible, you can configur a custom profile import like this:
*enigma is your FBA authentication provider name.
after user profile import is finished, you should be able to see your FBA users with "Name" property containing friendly "displayName" (assuming you have it in your LDAP data source, for example, ADAM)
You need to wait up to 1 hour for profile sync or my site cleanup timer job (see Spencer's article) to kick off (for profile sync, users need to be a site user in contrast to those user whose permission are assigned in application policy). Then close all your browser and log back in again, you will see friendly user display name in welcome menu.