HTC Desire :: Phone Run Out Of Memory

I got my phone yesterday and been playing with it since. Good bits-going on the net is quick, clear and very smooth. Customizing is very good. Bad bits-would have thought it would come with a video player that could play any type of format. I can't put apps onto mem card, thought the hole point of being able to put a large size mem card into the phone was so you could put all the extras onto the card. This is the main let down for me, got some apps on the phone last night then the phone said it had run out memory. I've seen that rooting can change this but don't fancy voiding my warranty. Wonder if a future update would cover this.