If phones are turning into miniature personal computers, there’s a need to fill many of the same software niches that computers have. A company called mBit is tackling data and downloading with the mobile version of peer-to-peer sharing, in which users swap photos, music and videos directly with each other.

MBit looks especially useful because phone hardware is advancing faster than the networks they work over. Cellphone cameras are becoming multi-megapixel, and their rapidly expanding memories are allowing storage of large amounts of music or video. But it can be nearly impossible to transfer a big file directly over a cellular network, especially with strict size limitations on multimedia messaging service (MMS).

Notably, mBit allows transfers to take place directly between two phones that are nearby to each other — in effect bypassing the cellular network. Transfers can also take place over carrier networks or on the Internet, through a WiFi connection. Like regular P2P, the files are transmitted in chunks, so the download can take place over time, stopping and starting again without problem.

According to CEO Chun Yan See, mBit has quickly gained in popularity since it was opened for at the end of last year for public download from getjar.com, with 208,000 downloads to date. That’s a good sign for the company, because like any P2P application, mBit rests on the backs of its users, making it important to the company to have as many of those as possible.

MBit itself maintains a centralized listing of all files, and users are allowed to share with other users around the world, creating a sort of global net. However, individual cellular networks can also run mBit for their users, charging a small monthly fee and reaping the benefits of reduced load on their network. So far, a pair of international carriers, Indosat and Smart, have signed on. For users who download the application on their own, mBit plans to run advertising.

The one drawback is that mBit isn’t available for all phones; right now, only Nokia and Sony Ericsson models, the most popular phones internationally, are supported. The company also has plans to develop a version for the iPhone. Owned by a larger company called mTouche, mBit itself is based in Singapore.

MBit is also one of our MobileBeat2008 nominees. If you’re interested in voting for it, you can do so here.