thats funny. I have a 17" samsung that sits on my desk, i come home, drop MBP in front of it, and never plug it in... sometimes it's not worth the hassle, and I guess the ability to switch apps easily makes it okay to not use an external screen.
must admit, I'm getting more into digital photography, and an ACD 30" is on my shopping list this year.
I spent a fair bit of dosh making my home office look nice, including new his and hers furniture.. it's not uncommon for me to come home from work, or wherever, and sit in the lounge room, watching some cable, with my MBP on my lap. (and a coopers in a glass) 🙂
I remember once i fired up google earth, on my external monitor, the next day I went to work, and went to use google earth again, and couldnt see anything, coz the window wouldnt appear on my primary MBP screen, it was still 'virtually' positioned for the external monitor! doh! wonder if the latest version fixes that.
I say plug that sucker in, throw some stuff up on it (safari, or itunes, or...) and enjoy it. make yourself use it more! who knows, you may find an ideal setup/config for your needs