From Microsoft Knowledge Base Article "How to manage .pst files in Outlook 2007, in Outlook 2003, and in Outlook 2002"
How to export .pst file data
If you want to back up only some of your Outlook data, you can create a new backup .pst file of only the data that you want to save. This is also known as exporting .pst file data. For example, you might want to use this section if you have important information in only some folders and you have other, less important items in much larger folders. You can export only the important folders or contacts and omit folders like Sent Mail.
Follow these steps to export a specific folder:
- Open Outlook.
- On the File menu, click Import And Export. If the menu item is not available, hover your pointer over the chevrons at the bottom of the menu, and then click Import and Export.
- Click Export To File, and then click Next.
- Click Personal Folder File (.pst) , and then click Next.
- Click the folder that you want to export the .pst file to, and then click Next.
- Click Browse, and then select the location where you want the new .pst file to be saved.
- In the File Name box, , type the name that you want to use for the new .pst file, and then click OK.
- Click Finish.
Transfer that saved .PST file to the new system by using your favorite transfer means. :)
To import into 2010 it's a little different (not much); To launch the Export/Import wizard, go to File menu, navigate to Open, and click Import:
Follow the wizard to import your previously saved .PST file.