OMG yes, being able to share jpgs, mp3s and even java apps from one phone to another via Irda then Bluetooth felt mind blowing in the early to mid 00's, considering that most people didn't have internet on their phones (2G/3G data plans were eye-watering at the time, hell, even texts were expensive) but their phones had this short range wireless sort-of-WiFi-ish capability on their phones for sending and receiving files from other phones or even desktop computers. For FREE!
I remember I would spend hours after school in Photoshop to turn an image I like into the perfect wallpaper for my phone, tuning the resolution and color gradient until it looked perfect on the phone's low resolution display, and using bluetooth to upload them.
Same with mp3s. Due to the low amount of storage on the early phones amounting to only a few MB, I spent a lot of time experimenting with aggressive compression to make sure I could fit as many songs on my phone as possible. Therefore they sounded pretty bad on the cheapo wired hands-free earphones that came in the box, but I didn't care or didn't bother to notice as I now had my favorite bands always with me in my pocket before MP3 players became affordable and I would just get lost in the lyrics on the bus to school.
On an old Symbian Nokia I had, once you paired it to your PC via Bluetooth, you could send and read SMS texts off it directly from windows just like I can now use Signal/Telegram/Whatsapp desktop clients. I didn't think this would be so mind blowing until I found that Android had no similar functionality built in at the time for SMS on desktop via Bluetooth (and still doesn't AFAIK) which really bummed me out that such a powerful OS with such powerful HW was so lacking in features compared to the dying Symbian.
Another fun anecdote, digging around my parents house this year, I found my ancient 2003 vintage NEC phone which had some VGA photos I took with it of me and my old school mates on it. When I saw that I could pull the photos off it in a pinch to my modern Android phone using Bluetooth, and immediately share them online with my former schoolmates from the photos, it was pretty mind blowing to say the least. Bluetooth gets a lot of hate today for connectivity issues some people face, but seeing it work reliably between vastly different devices almost 20 years apart is an amazing feat in my book and should at least deserve some praise.
Meanwhile, I couldn't change my 2006 phone's wallpaper without paying Verizon to enable the USB connection with a PC. I ended up taking a picture of the wallpaper using the phone, and then setting that image as the wallpaper. It was a 2-inch screen so it didn't look too bad.
Yeah I heard US telecoms were insanely draconic (why were they allowed to act like that though? lobbying?)
In Europe they weren't saints either but they weren't as bad when locking down your phone and mostly just resorted to SIM-lock, instead of locking other features as well.
From what I remember, Verizon did this with dumbphones, which I think ran similar OSes. So if you wanted to change the ringtone, you had to buy it from the crappy e-storefront on the phone. Same for wallpapers, and moving phone pictures to a computer via USB.
In 2008 I picked up a Windows Mobile 6.1 phone (Samsung Blackjack) that didn't have any such restriction. USB worked and it had a microSD slot for me to add in movies and music. I could crop an MP3 and simply transfer it to the Ringtones folder via USB mass storage.
Was there no way to flash it with a less restricted firmware? I remember running Alltel firmware on my Verizon Razr. And I was able to do similar things to the Rizr I got as my next phone.
In some areas of the world, this method seems to have persisted longer. Sahel Sounds released two compilations "Music from Saharan Cellphones" of tracks that they originally discovered on such bluetooth sharing networks: https://sahelsoundscompilations.bandcamp.com/album/music-fro...
(Though I'm pretty sure that they then went back and established traditional contractual relationships with the artists before releasing the compilations).
Man I remember drifting around the internet and finding the blog post about purchasing song .MP3s in a market and transferring them over bluetooth. At the time that seemed like such a cool and unexpected alternate evolution of purchasing songs from itunes.
Also, small java feature phone games! Was always a highlight when someone was "traded" a brand new feature phone game from another school, and it spread through ours within a day.
The Zune actually shared songs via WiFi. Microsoft unfortunately dubbed this feature "squirting" and initially had some silly DRM limits of three plays before the shared song expired. Nonetheless the Zune was an excellent music player.
There was a brief period while I was at school where people would share mp3 files with each other this way. This was before 2010.