This code and hardware schmatics are for a temperature controlled web enabled humidor.
The Dht22 sensor is installed in the humidor.
The arduino takes a reading every 20 minutes, and uploads the data to your webserver.
The PHP script will record the data to the database. If the temp or humidity is out of desired range, it will send you an email alert.
Alerts must be manually cleared latter by logging into the web site, so you are not spammed, before you get a chance to fix it.
When you add water, push the select button on the LCD sheild to record it. This will be saved to the db as well. Power resets will also be recorded to the database.
See screen shot for example web report.
More detail: Temperature controlled humidor with web logging