I put the RAM in my Macbook Pro without problem. Just use a #00 phillips to undo the three screws on the RAM cover in the battery compartment. Apple provides instructions, even: RAM is a user-replaceable part.
I'm planning to increase the size of the hard drive in my MB Pro, and BeamEcho (where I bought my machine) will upgrade with a user-supplied hard drive. They said it will cost around a hundred bucks for the work, and the Apple warranty will remain on the rest of the computer.
I was originally planning to buy the WD 320-gig hard drive, but then I started wondering about power consumption. It seems that the 320-gig drive I was looking at has significantly-higher power usage than the one I now have.
Here's the product sheet for the one I now have, the 120-gig Fujitsu MHW2120BH that came with my MB Pro:
http://www.fujitsu.com/us/services/computing/storage/hdd/mobile/mhw2160bh-sata.html
Here's the Tom's Hardware article describing the 320-gig drive, the Western Digital Scorpio WD3200BEVT:
http://www.tomshardware.com/2008/02/18/wd_and_toshiba_join_the_club/
Here's the Tom's Hardware article describing the 250-gig drive I was also looking at, the Hitachi TravelStar 5K250:
http://www.tomshardware.com/2007/11/15/travelstar_7k200_and_5k250_beat_the_band/
The Western Digital drive apparently has a SATA-300 interface, which draws more power than the SATA-150 interfaces of the Hitachi and Fujitsu. According to Tom, the WD drive draws 4.2 watts under load, and 1.1 watts at idle. The Hitachi drive draws 2.7 watts under load and 0.8 watts at idle. For comparison, according to the product page, the Fujitsu drive I already have draws 1.9 watts under load and 0.6 watts at idle.
http://www.tomshardware.com/2008/02/18/wd_and_toshiba_join_the_club/page7.html#power_requirements
I think I'll go with the 250-gig Hitachi drive; I'm concerned that the 320-gig will shorten my battery life too much. Anyone know what percentage of the Macbook Pro's power budget is taken by the hard drive?