To make you last a bit longer....
There is the practice makes perfect method which would mean the next time you have some free time just keep going at it one after the other, most guys I know will swear by this method it can be really irritating at first but when it comes right down to it the results are what your after!
There is the physical distraction by music method, which means you find a cd you really like listening to and meditate into the the beat of the music more than you do the task at hand ( slower music usually works better at first and as you get better at it you can usually pick faster music if your partner digs the more aggressive stuff, or start mixing your own discs and make them a little faster per song)
There is the Mental distraction by off the wall thoughts Method, which means whenever you feel like your close to climax you pop a completely off the wall non-sexual image into your head for a split second to push the point of climax back a little while longer and usually the stranger the image the better (example: two cartoon characters playing tennis... I got my friend hooked on that one in high-school and it really helped him out), but the picture doesn't really matter as long as it's a non-sexually stimulating thought!
There is always my personal favorite method, which is the taunt, tease, and please her to exhaustion method lol, which means learn to use your hands and mouth to please her first, my personal rule of thumb is I don't slide into a girl unless I've already got them off three to five times before I go for my own finish ( I don't know of one single girl thats ever complained about being over-satisfied sexually ) so take some time and learn her hot spots through a little foreplay, the rewards are well worth it! Believe me when I say a little self-sacrifice goes a long way, I learned along time ago its nice to get yours... but it's way better to give than to receive especially if you want her coming back again and again for more, and if you make it about her wants and needs it usually comes back ten fold!
The last thing I'll say is you need to spend a little time figuring out what kind of lover you are, some people are emotional lovers, some are physical lovers, and some are mental lovers, find your niche it's time well spent!
Hope that helps you out some,
LostInEternity