Internet Explorer is the worst browser ever, no doubt about that, yet, alas, it is still the most used one.
If you use Drupal you probably want to use the neat JSCalendar plugin, since it creates a nice date-picker for date fields. Unfortunately, the out-of-the-box version of it does not show datepicker icon in IE (it works just fine in Firefox/Safari etc.).
Apparently, the solution is to remove the following from jscalendar.css:
text-indent: -1000em;
