Wanna get a spectrum of recommendations from the broad church here.

Want something to install on my XP-based laptop to take away, but would equally like to be able to use it on a Blackberry (which I think I'll be issued over there) but also have the option of syncing across platforms in the future and maintaining a database of "buddies". Would be good if it could do Skype, but not essential. MSN is the main one. Would also love to be able to talk to Whatsapp (if that's even possible).

What does everybody use, and on what platforms?

So far, I was thinking Pidgin coz of the open source thing and my love for Firefox. But Trillian is looking increasingly sexy....

I use Adium (An OS X'ified Pidgin), or Pidgin on other desktop platforms.

On my iPhone I use a mix of IM+ Pro (all sort of IM services) and Colloquy (IRC only), I also use WhatsApp (I'm not sure that anything else can connect to their service).

I've found that friends no longer use MSN, out of the 30+ contacts I used to see online, I maybe see 3 now...I've switch to Google Chat as it offers better support for more platforms than just Windows.
Many friends use Facebook chat, but I refuse to use such rubbish.

My main form of internet chatter is here or via IRC...

I use Trillian from Cerulian Studios, there is a free version, but I have the paid for version "Astra", which means it manages all of my accounts in the cloud and I can log in on my iPhone, iMac, Windows or the Web with one username and password and all my IM accounts are automatically logged in.

If I am not on a normal computer, I can log in to the web interface and use it in the browser.

Very nice and very convinient. Just remember not to enter your password on an open computer (internet café etc.).

I used to use that (about ten years ago) for the month or so I actually used instant messaging.

MSN works very well on Blackberry. My boss used it constantly until we went 'droid.

All my friends either use MSN or nothing, so I just use the normal MSN on my XP machines. On the 'droid I've tried various clients, and Trillian is probably my preferred.

Hmmmm.... I thougth there would be more people using a variety of stuff on here.

Trillian does look cool and would allow Facebook chat without needing to be on Facebook. Which, let's face it, is unfortunately where a lot of people you know are likely to be.

How much did you pay for it Dave?

I use Kopete in KDE when I'm at my computer.

When I can't get at that, I use Meebo.com

I used to use Trillian oh so many years ago, when IMing was still cool.

Do enlighten me. What's cool now?

God knows. I decided to stop being cool several years ago. You still have your usual suspects of facebook and twitter. Having said that, I've been encouraged to download Whatsapp. It's essentially texting but it uses the wifi/3g/gprs connection to send them so there's no cost of texting. It's also quicker than texting too!

Whatsapp is bascially IM for the cool kids with smartphones. If I said that I could still remember my ICQ# from the over 10 years ago (21009889 btw) they'd look at me like I'm an alien. That said, if there was an PC/Mac/Linux IM client that could talk to Whatsapp, I'd be there.

I use Adium or when I have problems Yahoo and Microsoft messengers. I have not used ICQ for years.

I dont IM anymore. EVER. I used to use MSN a lot too!

I would say that I don’t IM now. I haven’t for a long time - probably when a friend moved from one company to another and the new outfit didn’t let him. The previous company was one we both worked for, and so the chatter looked kind of business related.

I started to find IM intrusive. There were some people, who through work, I kind of needed to be contactable to, who I could not tolerate one bit. He used to just pop up on the client, asking a snotty question about why I’d done something the way it was, without offering any better solution. Once people had moved on, I decided just to stop using IM.

Just looking at my IM client now, no one is on line. A few years ago, they would all be there. We just communicate in different ways now.

So maybe it is just more of a smartphone/portable thing now and not really applicable for my situation.