I have a Gateway MX6437 Laptop with the following specs

HArd drive BUS: Ultra ATA 133

OS: WIndoes XP with SP2
CPU Type: 1.8GHz AMD Turion 64 ML-32
Standard RAM 512 MB (removable)
Maximum RAM 2.0 GB
RAM Expansion 2 sockets
RAM Comments PC2700 DDR SDRAM SODIMMs

I understand that sometimes having too much RAM is useless due to processor-memory bottleneck, so given my Processor information, can anyone tell me would it make my computer faster if were to get a 1GB RAM and use it with the the existing 512mb RAM that I have (there are two slots). Thanks.

TBH I would go to the Crucial site and let that scan your system, it will list ram guaranteed to be compatible with your system and should make a great difference, and the price these days is so cheap it's a no brainer IMHO.
You will need to install and accept any prompts then it will list the best option first, done this for 2 mates now and each time they really felt the benefit, hope you do too.