One of the big plus points of an OLED screen is the fact it uses a lot less power than its LCD counterparts, which means a longer lasting battery - and the Samsung Jet S8000 certainly makes use of it.
We managed to get around one and a half days' usage out of it when leaning on the phone fairly heavily (one manufacturer once called us a power user... we didn't like that label as we have neither a Filofax nor do we 'do lunch' with 'Samson from Accounts') and even managed to coax two days' worth of use out of it when we realised late on that we'd forgotten our charger.
Using the 3G heavily isn't too bad either, with trying to download a million emails not de-juicing the battery too much at all, although we've yet to see such a system used over months and months, where it might suffer a lot more.
On the organisational side of things, the calendar and the memo functions are the only things that will really make a difference to your day-to-day life. The Memo application annoyingly doesn't let you scrawl down notes to yourself, which we find really helpful in a lot of phones, but the calendar works well enough.
The calendar on the Samsung Jet S8000 lets you work through all the important things and list them by importance, so if you need to see all the upcoming anniversaries (we assume Samsung means birthdays, not that this is a phone for polygamists or the unfaithful) then you can flash past the normal calendar screen to find them.