Three options I see with that bike:

1. Change to flat bar and find some 7 speed index thumb shifters. A new rear wheel will allow you to use a 7 speed cassette and there are cheap Shimano cassettes with 32 teeth large "granny" cogs like this: Shimano HG20 7-Speed Cassette from BikeBling.com You'll need new flat bar road levers too. These have a special cable pull so pay attention if/when you are buying them. You can't use v-brake levers.

2. Keep the drop bars and change to integrated shift/brake levers (aka brifters). This will likely require a new rear wheel, cassette, and probably rear derailleur. This is the most expensive option.

3. Change your crankset out (would require a new bottom bracket too) for a triple and find some triple stem shifters to replace the ones you have.

No matter what you do, new cables, housing, brake pads, lubing the chain (possibly replacement, depending on if it's rusty or not) and repacking the bottom bracket, headset and hubs will get you a long way in making it feel minty fresh.