We recently went live with out Sametime 7.5.1 servers so people now see their photos in the business card section, prompting many people to want a new picture, so the question arose after changing ones photo how long does it take for users to see the new photo. If a user has never had your photo before then it is almost immediate, however once I have seen your photo it is cached locally, and the client by default will not attempt download a new photo for 7 days. The default cache period can be changed by editing the plugin_customization.ini (in the directory where Sametime is installed) and add ‘com.ibm.collaboration.realtime.imhub/lookupExpirationDays=x’ where x= the number of days to cache the photo. You can set it to 0 to lookup the photo every time, but that could have an impact on performance. Technote 1264766 details all of the possible preferences that can be set via the plugin_customizations.ini, and technote 1261055 details how to package them up and send them to users via the update site. Finally if you are not using photos at all technote 1260018 details how to prevent users from seeing the empty gray box where the photo would be displayed.