You say you want a more "stable" system. Recall from your introductory economics courses that money has three roles: a medium of exchange (here is $, give me goods), a unit of account (you owe me $; the business made $ last year), and a store of value (I have saved $ for the future!).
I assume that you are mostly concerned with the store-of-value role being eroded due to inflation. But first consider that most people still want regular currency, so as a medium of exchange or accounting unit anything would face an uphill battle. If you discard that role for your currency, and only want to store value with it, you could just buy equities and commodities and baskets of currencies and debt in a brokerage account (possibly using mutual funds) to store your value. Trillions of dollars' worth of business takes place this way every year already.
Virtual currency was a bit of a dot-com bubble thing. The systems which didn't go completely bust and are still around have been beset by money-laundering, and otherwise remain largely an ignored niche.
An online fiat currency has the same basic problem that another currency has. You need to trust the central bank not to create more money and cause inflation (or even just abscond with the funds... or go bankrupt / get sued). Perhaps the Federal Reserve may be jerking us around on that front right now.... they're still a lot more believable than a small private institution. Some banks might possibly be trustworthy enough to launch a currency, but it's hard to see why they'd bother (it can't be a big profit center, because people aren't willing to pay too much to just use money.)
And an online currency that's backed by commodities (e.g. gold) is going to be subject to potentially violent swings in the prices of commodities. Imagine getting a loan out for your house, denominated in terms of e-gold, and then the price of gold triples. Ouch?