Here is a pretty cool trick that I learned (for a Mac, anyway. No idea if it works on Windows):
Go to Apple>System Preferences, then click on the Language and Text icon. Click on the Input Sources tab, scroll down the list (way down), until you see one of the sources following the US flag checked (assuming you are in the United States). Uncheck it, and check the "US international - PC" line.
You can now type accented vowels by first typing the apostrophe key, then the vowel. Get the ñ by holding down the option key, typing n, releasing the option key then retyping n.
If you do this, you will find out that trying to use the apostrophe or quote key normally returns abnormal results. No problem, type the key twice and it behaves normally.