Miscellaneous laptop discussions : Decisions, decisions......

Decisions, decisions......

I have a few notebooks that I can't decide between.
Some of these have been discussed here, and there are lots of differing views.
I seem to have narrowed it to: Sony Vaio VGN-S360P, Dell Inspiron 700m. The above 2 are around 4-4.2 lbs.
On the lighter side I also like Sony Vaio VGN-T250P/S, Dell Lattitude X1 and IBM ThinkPad x40. The Sony is 3.3 lbs. and a 10.6" screen, but has a built in DVDRW and CDRW. The other two are around 2.5lbs and do not have an internal optical drive.

My first criteria was that I wanted a really light notebook for everyday carrying and taking on trips. It will be for email, web surfing, digital photo storage and editing, as well as some financial tasks and charting. Even though I love the size and portability of the small Sony, its price of $2,300 and small screen size may not suit my needs. I know the Dell Inspiron 700m got good reviews both on CNET and by Walter Mossberg of WSJ, and it is the cheapest of them all. I am not sure if I will regret the weight for everyday portability.
I have a desktop with all the bells and whistles so I would not really need a DVD burner on the laptop.
I am trying to assess the pros and cons of not having an internal optical drive.
Would really appreciate some intelligent thoughts that may help me decide one way or another.
Also, the cost of extended warranty is so steep, I sometimes wonder if it pays to get it. Chances are in 2 years the computer will be obsolete anyway, no?