Crime and Disorder Act 1998 s.51. (Prior to the 1998 Act, even indictable only cases were subject to committal proceedings).
Another, rarely used, method is known as the Voluntary Bill of Indictment. Such a Bill has been used in the case of "Venables" who will stand trial in the Crown Court on charges relating to child pornography - see The Guardian 21st June. The charges are under the Protection of Children Act 1978 s.1 and, when tried in the Crown Court, the maximum sentence is 10 years imprisonment. In 1993, Venables, along with Thompson, was convicted of the murder of James Bulger. Following his conviction, Venables was provided with a new identity and this may not be revealed.
Grand Juries existed in England until the Administration of Justice (Miscellaneous Provisions) Act 1933. [Some of the history of grand juries may be read at R v Clarke, McDaid  UKHL 8]. Historically, Grand Juries came into being after the Assize of Clarendon 1166 provided for "Justices" to travel from town to town and to call upon freemen to report accusations of crime. This was one way in which Henry II wrested control from local barons to the Royal Judges. Over time, "Grand Juries" came to consider charges and to decide whether they should be tried. However, their use became superseded by committal proceedings before magistrates. The 1933 Act abolished Grand Juries which had, in practice, become something of an excuse for a "social junket" and were considered to be no longer serving a useful purpose. The Act permits a Voluntary Bill of Indictment to be issued with the consent of a Judge of the High Court. The use of this procedure is governed by strict rules and there is no hearing in the Magistrates' Court if this procedure is used. The usual occasions when this procedure is invoked are set out at CPS Legal Guidance.
Addendum 24th July: Venables received a 2 year sentence of imprisonment - see The Guardian 23rd July and also discussion of the legal issues raised by the case.