I doubled the ram on my Advent 4213 (same processor) to 2gb about 12 months ago. It's been very stable, can't remember it ever locking up; and the battery lasts for ages.
Money well spent, it's not expensive and you certainly won't regret it. Try Crucial
Mine came with 2gb but I'm happy to go along with the common perception that the extra RAM obviates much of the necessity of dipping into the hard drive for virtual memory - thus actually increasing battery life
i upgraded and the extra ram made no noticable difference whatsoever. It probably mades things happen quicker but you'd have to work hard to notice. Don't bother. Buy something shiny for you bike instead
The wee samsung is great on battery but compared to the sony vaio is painfully slow . Will the extra ram speed things up much ? , or should i invest in an ipad.