What i do to attempt reducing battery degrading is I usually discharge the battery once a week till it runs on reserve/empty and full recharge it back again. Things are bound to be worn off anyway, all you could do is reduce the wear.

you should discharge twice a month man, you are running down your battery cycle count.

I have a Macbook White (2006), Macbook pro 13 (2009) and Macbook Pro 15 (2009), there are no battery issues with any of them thus far,i only discharge(calibrate) once a month, use the magsafe whenever i'm at home, and when i'm at college i dont use the magsafe.

im using logitech premium usb hub (i think that's the name lah, powered one). i think it was rm80-90.
for those two stuff u mention, moshi is much2 better i've used capdase keyboard protector last time. too thick, n the surface is too smooth to type (no grip). bought moshi n couldn't be happier i also used moshi palmguard for both my MBP dy.

but palmguard have to be really careful when u install, dont bend it too much cuz it will leave white coloured creases on it. not really visible under fluorescent light but under sunlight very obvious n ugly +_+
yeap, new option since the day MBA was announced
OH MY GOD! faster leave ur laptop n run away from ur house, it's gonna explode anytime soon!!!

chill la, that's normal. what kind of battery stays at 100% health, im pretty sure we're still in 2010

I Guest it, because of your external harddisk formatted for windows machine, which is NTFS. Try format your external harddisk fo FAT32. So u can read and write in windows or mac. There is no official support from apple, to enable writing any data to your NTFS Harddisk.

open Disk Utility (use spotlight), select ur external hd on the left, to go Erase tab, pick format: FAT32 then click on Erase

the limitation of fat32 drives is u cannot store a single file that is larger than 4gb. no problems for folders, but not files

or u can just install ntfs-3g (free) to enable ntfs support. the transfer speed is really slow though. for faster speed u might wanna get tuxera ntfs or paragon ntfs, both are paid software. im using paragon NTFS n it works well

edit: can we have a sticky for this? it's an understandable problem for new mac users

@nike90,
i didn't know how amazing Google Search is.. 
Typed in a few words, and BAM! This came out.
http://support.apple.com/kb/ht1490