On PHPMaster.com there's a new article that suggests that suppressing notices thrown from your code is a bad practice to get into, both through error reporting and the use of the suppression operator, "@".
The PHP notice suppression operator is somewhat of a controversial topic in many circles. Some overuse it, some don’t use it at all, and some don’t even know it exists. Apologies in advance for the horrible code you’re about to witness in this article, but it serves a purpose to illustrate the usefulness (or lack thereof) of the suppression operator.
He talks about some of the common notices and how the suppression operator prevents the "Notice" message that could come out of it. They suggest, however, that there's never a good time to use the operator, especially during development. Obviously, there are a few cases (they point out one with mail) where it could be useful. There's also some sample code for a custom error handler you can use to capture the issues that might come up.