We control access to uploads and downloads, but with so many PDAs out there (both company-owned and personal), duplicate or incorrect data is always "appearing" in our contact databases because subtle differences (middle initials, addresses, phone numbers) fool the system into thinking the data is unique. Then the info is proliferated throughout the system because no one really has the time to check every entry. Any suggestions, besides asking our guys to be more careful?
That old IT bugaboo of "garbage in/garbage out" is alive and well, and even more vexing as more people are able to generate faulty information and input it into a centrally-shared data base. The best way to prevent it is to increase caution on the client side, and ask your users to be more careful when uploading information. Also if these users work from the same central resource, then it should be a relatively easy task to compare relatively similar contact files by matching up and automatically scrutinizing email addresses (since these entries will obviously be the least susceptible to screw ups and can be matched for duplicate records.
Most contact managers (Outlook, Act!, Goldmine, etc.) will automatically flag similar e-mails, and at least ask if you want to write over a current record in your personal data base (which should match up with the central file if you have been diligent about synchronizations and backups. We have also had great success using programs like AccuCard, which work CardScan to automate the contact entry process, and let you make corrections...
to entered data later in the day or week when you are not so busy. You can store this information in a personal Web space for viewing and reviewing, and then approve it for passage to the central information source during synchronization.
Some companies also use Plaxo, although many are skeptical and skittish about the way the software automatically talks with other Plaxo users to keep your contact data base up-to-date.
There are also some utilities available as shareware, although most companies frown on non-approved software of this type.
In the final analysis, the best way to limit bogus information is to increase quality control on the client side.