Here's more information - actually it doesn't look as depressing as you think!
http://www.irelandemb.org/living.html#req3. REQUIREMENTS FOR STAYS GREATER THAN 90 DAYS
Persons intending to stay in Ireland for a period greater than 90 days are required to seek permission from the Department of Justice, Equality and Law Reform within the first 90 days following their entry and preferably within a few days of their arrival. In the case of immediate family members of Irish citizens such extensions are usually automatic, although a formal application must still be made.
Persons seeking this permission should report for registration to the Aliens Registration Office, An Garda Síochána (Police Office), Harcourt Street, Dublin 2, Ireland or, if outside of the Dublin area, to their local Police Superintendent’s Office. An unauthorized overstay could result in prosecution, imprisonment and a fine.
The following documentation is required in support of an application:
completed Aliens Registration Form (available from local police offices)
a valid passport
four passport photographs
evidence where relevant of sufficient funds of support for the duration of stay (e.g. statement of earnings, bank statement, credit cards, ATM cards, traveller’s checks etc.)
Students and persons intending to take up employment in Ireland require additional documentation (see below)
Applicants may also be required to provide any information requested by an authorised official in connection with the purpose of their residing in Ireland.
If a person is refused permission to remain in Ireland they will be informed of the reasons for the refusal. Unsuccessful applicants can submit a written appeal against the decision.
In the event of not appealing the decision or the appeal being unsuccessful a person will be given a specified period of time in which to make arrangements to leave Ireland voluntarily. Failure to depart voluntarily could result in prosecution and/or deportation.
Further information on all of the above is available from the Immigration Section of the Department of Justice, Equality and Law Reform of Ireland, 72-76 St. Stephen’s Green, Dublin 2, Ireland (tel. 011-353-1-602.8202).
And here is the website with the contact numbers of the Irish Embassy in London:
http://foreignaffairs.gov.ie/embassies/display.aspGood luck