I have grown used to my iPad. The way we interact with iPads and other touchscreen devices is a lot more natural than 'designing with a bar of soap'. (yes- with a mouse). Mouse may have been a revolutionary product as the history of computing goes but it can never replace doodling out ideas on a piece of paper. iPad has brought back the playing in a sandbox feel. There's still a long way to go as far as serious production work is concerned but there is a lot of good stuff out there to make our life easier.
I'm on a quest to find good apps for architects. New apps as we all know are born every day and so no list of apps can be definitive but I'll go ahead and list out some of my favorites anyway. I'll try to stay away from CAD/Drafting apps as I have yet to find something that's useful and is not clumsy.
iBooks: Its free and it supports native PDF files and lists. A great way to carry all your reference material and flash cards (if you are cramming for LEED or AREs).
Adobe Ideas: My first serious app and it still sits on the first screen of my iPad. Works well with my fingers, supports layers and awesome 'markers on tracing paper' kind of coloring.
Zinio: When I moved to India from US I didn't want to lose my dose of dwell and Architectural Record. I decided to subscribe for electronic edition of both on my Zinio app and it turned out great. It's hard to forget the feel of a real magazine but Zinio makes it up in convenience and embedded videos and slideshows in otherwise static magazines. And I saved a bunch of trees from becoming paper pulp :)
Numbers: The first time I used it, I missed my laptop like crazy. But its a useful app from apple and works well with the desktop version of numbers and MS Excel. I say if you'd rather be a dork and work on a spreadsheet- do it in style. On a serious note, it's a useful app to have when you are not chugging your laptop around.
Keynotes: Another great addition from apple to create presentations on the move.
Pages: another 10 bucks and you are ready to create edit and share word/pages documents. At times I have hesitated to do a lot of typing on the ipad. It's not that I'm clinging to the tactile feel of the keys- infact I prefer to tap on my iphone than any other phone with a physical keypad, but you need to keep the ipad down on a table of your lap to use the keyboard effectively or hold it in one hand and type with a finger. I think things will be better with iOS5 which gives you the option of splitting the keypad to use as a proper thumb pad.
AutoCAD WS: Free app from AutoDesk to view, edit and share dwg files on your iPad.
iRhino 3D: View or present 3D models on your iPad. Supports Rhino .3DM files. I haven't used it as I don't use Rhino but if you do then $3.99 price can't be beat.
Punchlist: It's in my wishlist (when I get iPad 2 or maybe 3). How about opening a PDF floor plan and marking it up and taking pics as you walk the site. If any of you have used this app please share your views.
Houzz: Free app for some coffee break inspiration.
goBIM: View BIM files on your iPad. You'll need a goBIM exporter to create .gbz files for this app. I haven't used it yet but it sounds interesting.
Angry Birds: If you say it's got nothing to do with architecture, you haven't experienced it yet! There's nothing like a satisfying session of angry birds after a long day's work.