Bit more advice after looking through your blog.
1.) Top right hand corner, where you have the opt-in for your free eBook? Yes there. Within that box - you might want to add "type your email here..." or something along those lines. This will
GREATLY increase your magical list.
This is the basic code I use for feedburner or an opt-in box.
Code:
<input type="text" value="Type your email here" style="width:140px" name="email" onblur="if (this.value == '') {this.value = 'Type your email here';}" onfocus="if (this.value == 'Type your email here') {this.value = '';}"/>
2.) You don't just want to stop at 125 by 125. I would offer 160 by 600 and 468 by 60 banner placements.
There is no need to place a ton of boxes that read "advertise here" on every single page of your blog... I would take a screen shot of your website, and show them where they can advertise by placing boxes. Also link all your screen shots together so they can see the entire page (where advertising will be).
Few months ago I watched you ask questions about making money from a proxy. If you don't mind me asking - how much are you making from them in total? Oddly enough, I have a few proxies that bring in a few thousand unique people a day. Alexa ranks in the 100 - 200k's.
Cheers,
Kevin