A general rule of thumb would be that if it claims to come from a financial institution (AIB Customer Services or whatever) & requires you login to your account or otherwise confirm your details it's phishing.
Having a public email address I get several phishing emails a day for PayPal, eBay, US Banks, UK Banks, Irish Banks... I wouldn't even bother reading beyond the Subject / Sender.
Internet Explorer 7 & Firefox 2 both feature an integrated phishing filter which will warn you in the event you do happen to try load such a site (Assuming it's already been reported).