Does Anyone Know Any Temporary Solution for a Leaky Roof (Shingles)

@Muelitz (1592)
August 8, 2012 3:32pm CST
Our house roof shingle is supposed to be replaced in 4-5 years according to the building inspector. However, when it poured last week, water started to drip from our bathroom ceiling. I used a ladder to go up the access hatch to check it and did not find where the rain might have entered. I may need to wait for it to rain again. For financial reasons, we are not ready to have our shingles replaced so I am looking for alternatives to having it replaced of a temporary solution to my problem. I am not sure if some of you have been in this predicament before. If you have or if you know anything that I can maybe apply to my roof to make it last longer, i'd be glad to hear it. Thanks in advance.