You can change the time increments shown in your Outlook calendar to allow for smaller more detailed calendar entries. This will work in Outlook 2003, Outlook 2007, and Outlook 2010.
Outlook 2010 has a new feature called Suggested Contacts. This new folder collects e-mail addresses from ALL of the e-mails you send and receive. This can be a problem if you have a smart phone. The suggested contacts are automatically added to the contacts on your smart phone if Outlook is synched with your phone. You can disable the feature and delete the contacts from the folder. This will remove the contacts from your smart phone as well.