I am the happy owner of an HTC Touch. This page gathers a few tips and tricks I found on the net (or by myself).

Technical details

HTC P3450 Version 2
TI OMAP 850 (200 Mhz)
Windows Mobile 6 Professional
GSM/GPRS/EDGE: 900, 1800, 1900
Bluetooth 2.0
Wifi IEEE 802.11 b/g
ExtUSB

Changing the SMS center

Select "Telephone", then Menu, Options, Messagerie vocale et SMS and set the SMS center.

Synchronizing

System/Memory card

I found out an easy way to synchronize my HTC Touch with Linux. It is explained here. Actually, this is only a very basic synchronization tool:

install WM5torage on the device
plug the HTC Touch (USB cable)
activate the WM5torage tool

Then, the HTC Touch is seen as an USB key. You have direct access to the files from the PC. Unfortunately, you can only synchronize your additional SD Card that way, and not the device's own system memory (where contacts are located for instance)...

This strategy also works on Solaris:

install WM5torage on the device
plug the HTC Touch (USB cable)
activate the WM5torage tool
check where the device is mounted using df -h. For instance, my mobile phone's card mounts in /rmdisk/noname.

Google Agenda

I use GMobileSync. It's very simple to install and use (provide credentials and push the sync button !).

Thunderbird Contacts

I tried several solutions (Funambol server, BirdieSync...) and have finally settled to FinchSync.

FinchSync is definetely a developer's tool: an unattractive GUI with non-intuitive options ... but it works pretty well and does not put a mess on your computer. Problem: it does not synchronize all Contact information (additional dates, birthday, picture...).

Installation of FinchSync

Download FinchSync on your PC. This is a JAR, so it's OS-independant, provided there's a JRE on your system.
Download the .cab on the Pocket PC.

Configuration

On the PC

Launch FinchSync

java -jar FinchSync.jar

File -> Server Configuration: FinchSync launches a tiny web server. Set its port in that window. If you want to check server's status via a web page, mark the "enable status page" (optional - I haven't set it).
Sync Sources: I have created one source to synchronize my Thunderbird address book with my HTC. The .mab is located in thunderbird's profile. Assign a name to that source - this is just an identifier to refer to that source.
Clients: I have created one client, which is allowed to synchronize with my source. Specify a username and a password: this is the credentials you'll have to enter on the HTC. The conflict settings is "server wins".

On the HTC

First, configure a server (Config left menu):

server name: this is merely an identifier for your server's settings. It doesn't have to match your PC's name.
Host/IP: your PC's IP address
Port: enter the port number you specified on the PC.
Login, password: enter the credentials you chose on the PC for your client.

Then, go back to the first window, select your server, and hit the "Sync it!" button (beware: in some situations, having your HTC Touch directly connected to the PC via an USB cable forbids network connections. In that case, make sure to unplug the phone - or it will switch to GPRS/EDGE - so that the synchronization operates over the air). Of course, the FinchSync server must be running !

Network configuration

Wifi

To configure wifi:

the Wifi connection is set to connect to "Internet" (Paramètres -> Connexions -> Wifi)
to connect to the Freebox's wifi: use WPA-PSK with AES, and enter the key (password).

To see the curren status of one's connection: Paramètres -> Connexions -> Réseau sans fil

Connections to use

Paramàtres -> Connexions -> Connexions -> Avancés -> Sélectionner des réseaux: les programmes se connectant à Internet -> Internet les programmes se connectant à un réseau privè -> Rèseau de bureau

It's possible to change this by using always "réseau de bureau" (wonder what that means...), but then the wifi connection must be configured to connect to "réseau de bureau".

Changing location of "My Documents"

The best known solution consists in modifying the appropriate entry in the device's registry. However, this may be risky... A no-risk alternative consists in creating a link to another location.

Create a subfolder called "My Documents" in your Storage Card folder.
Copy the contents of \My Documents to \Carte de stockage\My Documents
Delete \My Documents
Open a text editor and paste the following text into a new document: "\Carte de stockage\My Documents"
Save this as "My Documents.lnk"
Copy this to the root of your WM6 device

Problem: ActiveSync keeps on synchronizing with a folder on the device , not on the storage card. The link works though.

Nice applications

Free internet browser: Opera Mini
My Mobiler: remote control your windows mobile from your PC, through an ActiveSync. Works great, as slow on the device :) It's also possible to take screen shots or videos of the device with that tool. (Freeware)
Total Commander: a better file browser/editor than the standard one. Though I'm not a fan of its layer, it's currently the best solution I know of to edit read-only files, system files or any other "strange" operation. (Freeware)
PIM Backup: backups your contacts, appointments, tasks, messages, calls... I haven't tried to restore, hope it works, but it looks great.