For those that say that the 700m has certain advantages over the Sony S360, may I ask what they are? The only advantage I can see is price. Their sizes are pretty much the same:
Sony Vaio VGN-S360
Dimensions: 12.3" x 8.9" x 1.4"
Weight: ~4.2lbs
Dell Inspiron 700m
Dimensions: 11.7" x 8.5" x 1.5"
Weight: ~4.1lbs
Yet the S360 packs a 13.3 WXGA LCD versus a 12.1" WXGA LCD on the 700m, and the S360 also packs an ATI 9700 64mb dedicated video card, which is clearly superior to the Intel Integrated video card in the 700m. As such, I urge all of you to consider the Sony Vaio VGN-S360 if you're planning on buying the Dell Inspiron 700m without using any Dell coupons (why would you not in the first place? lol). I believe you can buy a new Sony Vaio VGN-360 for $1599 after a rebate or two, although the S360's are a bit hard to find nowadays since they've been succeeded by the S380/S460 (which IMHO, as well as a bunch of other members on this forum, feel are actually inferior to the "older" S360/S270....less battery-life, worse video card, runs hotter, etc.).
The way I see it, at Dell's current prices and built-in/instant promotions (20%off), you can buy a 700m with a similar configuration to the S360 (1.6GHz, 512mb RAM 1dimm, 80GB HDD, 24x CDRW/DVD combo drive, 802.11b/g wireless, 1yr warranty, 4cell standard battery) for $1262. Or most people here would probably spend $1102 and opt for just 1x256mb RAM, but buy another 256mb stick of RAM for ~$30. So it'll end up costing your $1132-$1262 for a new Dell 700m with similar specs to the S360 at "regular price". So whether or not the extra $337-$467 is worth it to upgrade to a S360 with a bigger LCD (13.3" versus 12.1") and a significantly better video card (ATI 9700 64mb dedicated versus Intel Integrated which shares RAM with your system RAM) is up to you. Also, some say the S360 has bettery build-quality than the 700m, but thats kind of subjective, and I haven't seen a 700m in person, so I cannot say.
If you don't play any games, and get in on one of Dell's seemingly regular $750 off $1499+ purchase coupon promotion, then getting a Dell 700m for ~$750 is a no-brainer (the last coupon could have bought you a 1.6GHz, 256mb RAM 1dimm, 40GB HDD, 8x DVD burner, 802.11b/g wireless, 2yr warranty 700m for $750!!!! 2yr warranty and a DVD burner, WOW!
So no doubt about it, the Dell 700m is a MUCH better value, if you happen to catch a $750 off $1499+ coupon, and don't plan on playing any games. However, if you plan on getting a 700m at "regular price", or need/want to play games, you may want to consider the Sony Vaio VGN-S360.
There's my quick summary of my thoughts/opinions lol, sorry if it got so long. Most people claim to have no problems video editing on the Intel integrated video card on the 700m, so its a matter of if you want to game or not that'll decide if you need a S360 or not. I personally think that the Sony Vaio VGN-S360 is perfect for me, since I tried both "desktop replacement" (Gateway M6805 and Dell 6000d) and "thin-and-light" (IBM T40 and Dell 600m) laptops, as well as those in between the two categories lol (Compal CL56...6.25lbs). The "desktop replacements" were quite powerful, and satisfied all my gaming needs, but were just a bit too heavy at 7+lbs to be very feasible to carry around 5hrs+ daily. The "thin-and-lights" were fine for portability, but their video cards weren't nearly as powerful as I would have liked (ATI 9000). To find a laptop that is even lighter/smaller than the "thin-and-lights" that I have used, yet still packs a reasonably powerful video card (ATI 9700)? That's perfect for me! I can't wait to get my S360 on Friday! I was going to pull the trigger on the 700m for $750, and just deal with not being able to play many games, but then i heard about the sony S360.
In the end, you have to thoroughly analyze what your needs are as well as your budget. You'll be hard-pressed to find a Sony Vaio VGN-S360 for less than $1599 new (unless you try your luck on eBay) or otherwise, a used one on eBay/forums can be had for $1100-$1400. In contrast, a new 700m can be had for $750-$1262 with similar specs to the S360 (sans the video card of course). So decide if you want to play games or not, and go from there

. Good luck!