How to increase the internal memory of HTC desire GSM? I have S-offed my phone installed the rom oxygen with HBOOT oxygen_r2. My internal phone storage was almost doubled from 115 MB left before installing HBOOT and now it is 298 MB left after installing oxygen_r2 HBOOT with oxygen 2.3.2 rom. 

After that, I have flashed the new recovery from Clockworkmod 5.2 .. or something to with 4EXT recovery but now there is no increase in memory after I have flashed the new recovery. I still left with 298 MB Internal Memory. 

Can someone please tell me how to increase more internal Memory other than using ext partition? Does changing recovery image will increase memory as just I did ??
300MB are the absolute maximum you can get without having an EXT4 partition on the sd card as a replacement.
Having a look at http://alpharev.nl/ you see that there's only a 330MB partition left, however none of my preferred ROMs fit that. It's made for some special ROM called Oxygen which I didn't like. 

With custom CM9/CM10 builds however I had to switch back to Bravo Stock again and I set up an external EXT4 1GB partition on my SD card. Those 1024MB are far better than having 30MB more (330MB instead of close to 300MB).