Thanks for the suggestion. I looked and you are correct that there are no built in join strings for the relationship between users and peripherals.
I did add this in the development build so it will be included in the next release.
In the meantime I believe the following will meet your requirements if you create a custom SQL report.
SELECT tbl_user.UserDept, Peripheral.periphTag, PeriphUserID, Peripheral.periphManufacturer, Peripheral.periphModel, Peripheral.periphClass
FROM tbl_user INNER JOIN Peripheral ON Peripheral.PeriphUserID = tbl_user.userID
WHERE (((Peripheral.periphClass)="Cell Phone"))
ORDER BY tbl_user.UserDept, Peripheral.PeriphUserID;
You may need to change "Cell Phone" to your appropriate Peripheral Type.