We released a new version of the popular Outlook Plugin for vtiger CRM v.5.2.0. You may find the details at the vtiger forums entry.
This version comes with a couple of enhanced features and improves the synchronization speed significantly. You may use these features also for CRM 5.1 if you follow the instructions given in the forums.
Thanks to the help from the community the Plugin includes localizations for English, Spanish, French, Dutch, German, Italian and Portuguese. If your language is missing and you would like to help us, please contact crm-now. Making a translation of the language files is about 1 hour work.
For a download look up the vtiger Extension page.