Well, one thing that you could do is convert it into a boat anchor....
Seriously though, you can turbo it, but it will be only a matter of time before it blows up. And you'll have spent close to what it would cost for a WRX swap. (3-4k) Just look up Kostamogen.
As far as engine swaps, the search button is your best friend. But, since you just recently joinrd up, I'll give you a few leads.
First off, is your car a sedan or wagon? AWD? Standard or Auto? What is the condition of the car? What do you plan on doing with it?
You can do any swap that you want, provided that you have the time and money. The cheapest and the easiest to do are:
IIRC, the 2.2 from a similar year will plug right in. You can normally find those for about $300.
OR, you can get your hands on a 2000-up EJ 2.5. (Legacy, Forester, Impreza RS 2.5 liter N/A) With very little work you'll get 165 HP for about $800. Add on some cams, equal length headers, air intake, thin headgasket, and you'll be close to 200 HP.
All of this off the 1.8 ECU. That means zero wiring. You will have to run at least 91 octane, or you'll have a lot of knock.
Other swaps that you could do are: V.2 or V.3 JDM WRX swap. You'll get about 230ish HP for about $2500. There isn't as much wiring as a USDM WRX, but if you live in an area that does emissions testing, you're pretty much outtta luck.
Then that leaves us with the USDM WRX and STI motors. Lots of wiring to do. It's not a really hard job, just time consuming. For more info. READ THE STICKYS!!!!!!!
(BTW, did I mention that the search button is your friend?)