wow, that's really interesting that this subject has been brought up, cause i just finished writing an article about this for the upcoming stp blog.
i currently own the Eee PC 1000HD, and in terms of size/weight, it's amazing. ive even been doing a lot/most of the website maintenance on it. my only complaint so far is that ubuntu seems a bit sluggish with 1gb ram. im pretty happy with xubuntu, although i have it set up for dual boot with windows xp because google earth kinda runs like crap in ubuntu (and i still use itunes for my ipod - god im a gadget geek).
but yeah, i paid 400 for mine. ive had it for about 4 months now, and they're getting cheaper and with more features all the time. widerstand just showed me an eee pc model he's looking at for 300 with twice the features mine has. damn!
but yeah, i have not personally used the acer or many of the other "ultra portable" lappys that are out now, but in terms of specs, the eee pc is waaaay better than the acer, hp mini, etc. just don't expect to run photoshop cs4 or anything crazy like that.
suprisingly though, photoshop cs3 works pretty well.
but yeah, i wouldn't advertise the fact you have a laptop to a lot of people depending on the situation youre in (like the squat mentioned above).