I was thinking of buying this game but, I never played the original Half Life.  So will I be lost in Half Life 2?

No, you won't.
You can always look up a plot synopsis if you have to.

Thanks I was going to look into it a little i just wanted to make sure it wasn't super deep.

I'm currently playing through orange box and I never played the first Half Life, I think it all makes sense.

You don't need to play HL1 to enjoy HL2 at all...and it will make enough sense for newcomers to the series.

Coming from the exact situation as you, i juz read the dstory background on wikipedia and jumped straight into half life 2 and the episodes.
I found it enjoyable and totally not feeling that i was left out due to the fact that i missed the last game.
Or you can go buy the original half life now, i bet they are dirt cheap now.

Narr, you could probly skip HL2 and go straight to EP2 and it would probly still make sence.
But you dont need to know anythin about the original to enjoy it. I never played the first and HL2 is still one of my most favourite games of all time.

I've never played it and I'm still playing this game. It's not confusing at all.

As a person who played the first game I can tell you that its much less jarring to play Half-Life 2 if you haven't played HL1.

It may seem strange but, for me at least, going to HL2 from HL1 I was very confused for a little while. I made false assumptions about the combine, didn't understand why the vortigaunt are human friendly now etc.

HL2 kind of turns all you know from HL1 on its head, so aside from not getting some references, in jokes, and returning characters you'll be fine.

Is HL1 still worth picking up and playing? Or has HL2 made it sort of irrelevant? And I suppose I should mention I'm referring to if the PS2 version is worth finding and picking up.

"Is HL1 still worth picking up and playing? Or has HL2 made it sort of irrelevant?"

I never played HL1 before playing the Orange Box, and all the HL2 games made perfect sense and were really fun

Regardless, you should really play Half-Life 1 anyway. 'Tis good.