The biggest catch here will be to make sure you have compatible ram.
PC2700 refers to speed. In this case, 333MHz.
400 also refers to speed, but is used to refer to 400MHz sticks.
PC2700 = DDR333 = 333MHz ram.
PC3200 = DDR400 = 400MHz ram.
If you want to do some research,
Newegg.com - Computer Parts, PC Components, Laptop Computers, Digital Cameras and more! has reviews. If you find some ram where the reviews mention your intel chipset, you're good to go.
Otherwise
Upgrade Dell Computer Laptop Memory, IBM, Lenovo - identify RAM DDR DDR2 DDR3 modules has guaranteed compatibility. Just search based on your motherboard make/model.