Every now and then, Google reminds everyone of how some of its features depend on the kindness of strangers.

Examples of this can be found by visiting the blogs of Google Base, a free classifieds listing feature, and Google Talk, which is Google's version of an instant messenging app for PCs.

Google left implicit instructions April 10 on its Google Base blog about how those uploading a listing can create new listing categories.

The firm wants to come up with 40 new categories for Google Base, and plans to pick from the ones Google Base users create, writes employee Steven De La O. So get busy creating those new categories, he writes.

On April 12, Google cracked the whip again, asking for help improving the way in which you can bulk-upload items to Google Base.

On Google Talk's blog, Brian McBarron, a Google software engineer, on April 10 steered readers to a Web site where enthusiasts make available their own versions of software to customize Google Talk's on-screen look. He too left some implicit instructions on how to upload items.

Google's not the only high-tech company to ask its customers for help. But Google seems more dependent on its users' spirit of volunteerism than other companies. Perhaps it's due to how a number of Google features depend upon consumers providing the material, not Google. So it's no wonder if Google cracks the whip now and again.