Facebook is trying to make it easier for people to share their updates selectively and draw distinctions between friends, family members and co-workers on the Web’s biggest social hub.

Mark Zuckerberg, Facebook’s founder and CEO, unveiled the latest changes Wednesday at a press conference that marked his first public appearance since last Friday’s debut of “The Social Network,” a movie tracing Facebook’s origins and evolution.

A BitTorrent app called IS Drive has appeared in Apple’s App Store for iPhone, iPod touch and iPad, despite the company’s past refusal to approve BitTorrent apps because they could be used for Internet piracy.

The app is intended as a tool for managing ImageShack (ImageShack)’s torrent download service, but it can be adapted to manage downloads from other torrent sites like IsoHunt and Mininova.

Google is introducing a new format for images: WebP.

Images on the web in this format — which CNET reports will be officially announced later today — will have smaller file sizes, load faster and relieve a lot of overclocked networks. They won’t necessarily look better — WebP images are as “glossy” as JPEGs — but the files might be around 40% smaller than JPEG files.

And since Google (Google) estimates 65% of the bytes on the web are images, that represents a quarter of the total amount of data we access and transmit online. Who wouldn’t change formats for a web that could be 26% faster?

Advertisers will be allowed to purchase placement in lists of “who to follow” recommendations targeted to users with particular interests on Twitter, according to the latest report by Peter Kafka on the Wall St. Journal’s AllThingsD. Kafka reports that the new ad model will be unveiled at the IAB conference in New York City tomorrow.

It’s against Twitter’s Terms of Service for outside parties to sell followers on the popular messaging service, but that’s not just because Twitter wants all the revenues for themselves. Most “buy followers” services are completely untargeted and negatively impact the user experience on the network. This new feature may work out very well for all parties involved, including Twitter users. Early reaction on Twitter, however, is not positive.

Iran, which acknowledged earlier that many of the computers in its nuclear operations have been attacked by the Stuxnet worm, has arrested an unspecified number of “nuclear spies,” its intelligence minister, Heydar Moslehi, said Saturday. No details on the arrests were given, and the arrests could not be independently verified.

The Stuxnet worm targets Siemens SCADA, or “supervisory control and data acquisition” systems. Those systems are commonly used to manage oil rigs, power plants, water facilities, and other industrial plants.

Because of the sophistication of the Stuxnet worm, many believe it was developed by some government’s cyber intelligence agency, and was created with Iran as a specific target. The worm has surfaced in other countries as well, however.

Microsoft Corp. is suing Motorola Inc. for infringing on its smart-phone patents.

The software maker on Friday said Motorola phones that use Google Inc.’s Android software step on Microsoft technology. The functions in question include synchronizing e-mail, calendars and contacts.

Microsoft filed its lawsuit in the U.S. District Court for the Western District of Washington. It also filed a claim with the International Trade Commission.