well i downloaded wormux and enjoy playing it..not to mention some gameboy and nintendo emulation 

First, you need to have the right repository set for your application manager

http://blog.kiawin.com/2010/02/nokia-n900-3-more-apps.html
Then, in your "Application Manager", Go to "Desktop", you should be able to see the "USSD widget"

i think you can set the details of your USSD when you edit the widget look for the spanar

Public hotspots free

FTW 

lol what is Wifi? have to pay? well if u dont know something like this, might as well get some simple phone instead of a phone with such OS

sigh, really a waste of time and effort explaining to this dude who don't even know how to differentiate 3G & Wifi access...

Public wifi(such in cafes & university campus) are free to use.

Perhaps your phone connected to 3G instead of WiFi?
Did you try asking for explanation from your service provider?

OLOLOLOLOL........sorry2 but this is so LOLworthy
Anyway are u using online widgets on ur desktop (facebook etc)? Mybe that could account for ur extra bill

u win dude!!!! u win!
dont click

How sure are you that your phone didn't automatically connect to 3G?

Go To Settings --> Internet Connections
Make sure the settings does not connect automatically for 3G Internet.

If there is automatic connection, you might not know when your phone updates automatically using 3G Internet.

If you install any widgets that have auto-update (default settings) and you didn't disable it, it will use the default connection. Even your email and so on does the same. Same goes for Nokia Maps.

Lastly, to check if your phone has used any Data Packets, go to:
Settings --> Phone --> Scroll Down to the end and choose "Data counter"
This will show you the total MB send and received.
Alternatively, you can also install the "Dataplan Monitor" widget.

which means you have used data transfer of 85mb...
if you don't have unlimited data plan then multiply it with pay as you go charge per kb.

let say PAYU rate is 10 sen per 10kb, so 1mb= RM10...your total usage now is RM850 for data only 
if you're on digi, they will capped for data charges once you  reached RM149 amount of usage, after that it is free for the current month cycle.

---

Added on February 26, 2010, 12:11 pmfor me if you buy a smartphone like iphone, nexus one etc but do not subscribe to unlimited data plan it was like pointless buying the phone right??

those phones are designed as internet on go the type of phone...if you're on celcom or digi network...unlimited data plan is not that expensive..RM58/month for digi and rm68/month for celcom..

Thanks bro!
Yup, it's good news, more accessories and also support and parts from Nokia (for those who prefer to get from Ori store).
Now it's clear that your phone does indeed use data plan (e.g. 3G). Try to set your phone to not connect via 3G or data packets automatically. Even other N series like N81, N97, etc they have automatic connection to 3G or your network data usage, you have to disable it or choose "Always Ask" for these type of connection under the settings. That's why many people have "unknown" usage on the data.

When your wifi is not available or disconnected, and some apps/email/gps wants to update, it will automatically use the next available connection, which will be your network data (e.g. 3G) automatically unless you specify not to use it automatically.
Since your usage is so high, I suspect it's the email retrieval or downloading of apps. Or it can be some other things that is using your network data plan.

Tips:
1. Try connecting to WiFi and see the wifi connection icon beside the battery icon.
2. Try connecting to 3G and see the 3G connection icon beside the battery icon.
Both these are different icon, so it can somewhat help you identify which connection you're on.

If you're on Maxis, maybe you can consider subscribe to 500MB plan for 3G Internet which is RM58; or  switch to DiGi for unlimited plan for the same price! woot!
For Maxis, just login to maxis.com.my, and you can activate immediately.

Lastly, to monitor you data plan easily, install the "Dataplan Monitor" widget and put in your desktop. You can see in real-time your data plan usage, and take action quickly if you suspect any changes. (find the culprit)

same thing happen on me for d 1st time when i use this phone..i never expect it auto search connection and connected to 3g..my bill last month rm149 for internet T___T

oh btw i m digi telco

been using this babe for almost a month and still liking it ..looking for more apps for it